2โ€“6 Sept 2024
University of Southampton
Europe/London timezone

Session

Parallel sessions

2 Sept 2024, 14:00
University of Southampton

University of Southampton

Highfield Campus Southampton SO17 1BJ

Conveners

Parallel sessions: QFT I

  • There are no conveners in this block

Parallel sessions: Resurgence & non-perturbative methods I

  • [Convener: Daniele Dorigoni]

Parallel sessions: Bootstrap I

  • [Convener: Balt Van Rees]

Parallel sessions: Black holes

  • [Convener: Alejandra Castro]

Parallel sessions: Holography (applied) I

  • [Convener: Aristomenis Donos]

Parallel sessions: Symmetries

  • There are no conveners in this block

Parallel sessions: Bootstrap II

  • [Convener: Shai Chester]

Parallel sessions: Holography (applied) II

  • [Convener: Michal Heller]

Parallel sessions: Supergravity I

  • [Convener: Dario Martelli]

Parallel sessions: Holograhy (flat) I

  • [Convener: Tim Adamo]

Parallel sessions: Swampland

  • [Convener: Miguel Montero]

Parallel sessions: Amplitudes

  • [Convener: Oliver Schlotterer]

Parallel sessions: Holography (flat) II

  • There are no conveners in this block

Parallel sessions: Cosmological bootstrap

  • [Convener: Massimo Taronna]

Parallel sessions: Black holes and quantum information

  • [Convener: Julian Sonner]

Parallel sessions: Supergravity II

  • There are no conveners in this block

Parallel sessions: Non-relativistic field theories

  • [Convener: Jelle Hartong]

Parallel sessions: Generalized symmetries

  • [Convener: Lakshya Bhardwaj]

Parallel sessions: Holography

  • [Convener: Shira Chapman]

Parallel sessions: Cosmology (formal, string cosmology)

  • [Convener: Viktor Gorbenko]

Parallel sessions: Holography (flat) III

  • There are no conveners in this block

Parallel sessions: QFT II

  • [Convener: Christopher Beem]

Parallel sessions: CFT

  • There are no conveners in this block

Parallel sessions: Resurgence & non-perturbative methods II

  • [Convener: Ines Aniceto]

Parallel sessions: AI & machine learning

  • There are no conveners in this block

Presentation materials

There are no materials yet.

  1. Balt van Rees
    02/09/2024, 14:00
    Talk in parallel session

    We set up a numerical S-matrix bootstrap problem to rigorously constrain bound state couplings given by the residues of poles in elastic amplitudes. We extract upper bounds on these couplings that follow purely from unitarity, crossing symmetry, and the Roy equations within their proven domain of validity. First we consider amplitudes with a single spin 0 or spin 2 bound state, both with or...

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  2. Aristomenis Donos (Durham University)
    02/09/2024, 14:00
    Talk in parallel session

    I will discuss the low energy dynamics of finite temperature systems which are close to a superfluid phase transition. In the regime, the amplitude of the order parameter needs to be included in the description captured by the hydrodynamics of conserved quantities and the Goldstone mode. After presenting a field theoretic construction of a suitable effective theory, I will examine the...

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  3. Lorenzo Ruggeri (Tsinghua University)
    02/09/2024, 14:00
    Formal QFT 2
    Talk in parallel session

    Non-invertible symmetries in general spacetime dimensions have attracted many attentions recently. I will present novel results for duality defects in 2+1 dimensional theories with $\mathbb{Z}^{(0)}_N\times\mathbb{Z}^{(1)}_N$ global symmetry and trivial mixed 't Hooft anomaly. By gauging these symmetries simultaneously in half of the spacetime, duality defects can be constructed for theories...

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  4. Tomรกs Reis (SISSA)
    02/09/2024, 14:00
    Resurgence and non-perturbative methods 1
    Talk in parallel session

    Following the example of previous work by Benjamin et al. and Kaplan et al., we look at the large charge expansion of the identity block in CFT2. The motivation is clear in AdS/CFT: to look for black holes in the graviton expansion! We start by exhausting the resurgence analysis of four-point function of the (2,1) degenerate fields at finite cross-ratio z. We see that Stokes phenomena in the...

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  5. Alejandra Castro
    02/09/2024, 14:00
    Talk in parallel session

    Modular forms play a pivotal role in the counting of black hole microstates. The underlying modular symmetry of counting formulae was key in the precise match between the Bekenstein-Hawking entropy of supersymmetric black holes and Cardy's formula for the asymptotic growth of states. The goal of this talk is to revisit the connection between modular forms and black hole entropy, and tie it...

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  6. Nika Sokolova
    02/09/2024, 14:30
    Bootstrap (CFT, S-matrix) 1
    Talk in parallel session

    We consider 4d N=4 SYM theory in the planar limit at strong coupling. We focus on โ€œstringyโ€ operators which are single-trace operators accessible by integrability (for example by the Quantum Spectral Curve). We discuss how to assign stringy operators to KK-towers on AdS5 \times S5 and how the degeneracy of excited strings breaks.

    We use these observations to lift the degeneracy of the...

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  7. Andre Oliveira Pinheiro (Heriot-Watt University)
    02/09/2024, 14:30
    Holography (applied) 2
    Talk in parallel session

    The hydrodynamics of crystals without topological defects (e.g. dislocations) can be accounted for by considering a set of 2-form global symmetries. In thermal equilibrium, the holographic dual to such a crystal is an AdS black brane charged under 2-form gauge fields. By extending the fluid-gravity correspondence to such backgrounds we obtain both dissipative and non-dissipative transport...

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  8. Paolo Vallarino
    02/09/2024, 14:30
    Resurgence and non-perturbative methods 1
    Talk in parallel session

    I will discuss recent developments in the study of integrated 4-point correlators of primary operators in a four-dimensional $\mathcal{N}=2$ superconformal field theory with $SU(N)$ gauge group and matter in the fundamental and anti-symmetric representations. Exploiting supersymmetric localization, it is possible to map the computation of these correlators to an interacting matrix model and...

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  9. Marina David
    02/09/2024, 14:30
    Black holes
    Talk in parallel session

    Two universal predictions of general relativity are the propagation of gravitational waves of large momentum along null geodesics and the isospectrality of quasinormal modes in many families of black holes. In extensions of general relativity, these properties are typically lost: quasinormal modes are no longer isospectral and gravitational wave propagation is no longer geodesic and it...

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  10. Mr Souparna Nath (Tata Institute of Fundamental Research)
    02/09/2024, 14:30
    Formal QFT 2
    Talk in parallel session

    Most of the computational evidence for the Boseโ€“Fermi duality of fundamental fields coupled to $U(N)$ Chernโ€“Simons theories originates in the large-N calculations performed in the light-cone gauge. In this paper, we use another gauge, the โ€˜temporalโ€™ gauge,
    to evaluate the finite temperature partition function of $U(N)$ coupled regular and critical fermions on $\mathbb{R}^2$ at large $N$. We...

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  11. Francesco Galvagno (Queen Mary University of London)
    02/09/2024, 14:50
    Resurgence and non-perturbative methods 2
    Talk in parallel session

    Integrated correlators in N=4 SYM represent a powerful tool to obtain exact results in the coupling constant, and can be used as constraints for dual string scattering amplitudes in AdS. In this talk we study special classes of integrated correlators, dual to scattering processes in presence of extended branes in the bulk. First, we consider 4pt correlators with determinant operators, which in...

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  12. zhenghao zhong
    02/09/2024, 14:50
    Formal QFT 2
    Talk in parallel session

    We explore supersymmetric QFTs with eight supercharges. At superconformal fixed points, these theories typically lack a Lagrangian description, complicating their study. Recently, the magnetic quiver has been proposed as a tool to encode the Higgs branches of these theories. Utilizing this tool, our recent papers [1,2] propose a new algorithm: Decay and Fission of Magnetic Quivers, which...

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  13. Panagiotis Charalambous (SISSA)
    02/09/2024, 14:50
    Black holes
    Talk in parallel session

    It was recently remarked that the hypersurface of null infinity of asymptotically flat spacetimes is a non-expanding horizon. We utilize this observation and propose a duality between the asymptotic structure of asymptotically flat spacetimes and the near-horizon structure of extremal black holes. The link between these two classes of geometries comes in the form of spatial inversions that...

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  14. Vaios Ziogas (Bristol University)
    02/09/2024, 14:50
    Holography (applied) 2
    Talk in parallel session

    The complete description of non-equilibrium quantum dynamics necessitates the use of the so-called doubled Schwinger-Keldysh contour in complex time. Recently, Glorioso, Crossley and Liu proposed a convienent prescription for obtaining such SK effective actions from holography, by considering a specific contour in the complex bulk radial plane.
    In this work we show how the GCL prescription...

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  15. Mr Biswajit Sahoo (King's College London)
    02/09/2024, 14:50
    Bootstrap (CFT, S-matrix) 1
    Talk in parallel session

    I will describe how various vertices and scattering amplitudes, involving background fields, probe trace anomaly coefficients in a four-dimensional (4D) renormalization group (RG) flow. Specifically, I will explain how to couple dilaton and graviton fields to the degrees of freedom of 4D QFT, ensuring the conservation of the Weyl anomaly along the RG flow for the coupled system. By providing...

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  16. Mariana Carrillo Gonzalez (Imperial College London)
    02/09/2024, 15:10
    Black holes
    Talk in parallel session

    In flat space, it is well understood how to obtain gravity by "squaring" gauge theories through the double copy. This holds for scattering amplitudes and classical solutions (in coordinate and twistor space). In the past few years, it was realized that the Penrose transform explains the existence of a classical double copy and that this realization can be extended to 3d spacetimes for wave...

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  17. Christiana Pantelidou (University College Dublin)
    02/09/2024, 15:10
    Black holes
    Talk in parallel session

    We investigate the stability of the spectrum of (scalar, vector and gravitational) quasinormal modes of electrically charged black branes in asymptotically AdS5 spacetimes under small perturbations of the theory. To achieve this, we formulate the problem as a generalised eigenvalue problem in ingoing Eddingtonโ€“Finkelstein coordinates, which is advantageous in terms of numerical convergence....

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  18. Dr Arnab Priya Saha (Indian Institute of Science)
    02/09/2024, 15:10
    Bootstrap (CFT, S-matrix) 1
    Talk in parallel session

    Motivated by quantum field theory (QFT) considerations, we present new representations of the Euler-Beta function and tree-level string theory amplitudes using a new two-channel, local, crossing symmetric dispersion relation. Unlike standard series representations, the new ones are analytic everywhere except at the poles, sum over poles in all channels and include contact interactions, in the...

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  19. Ms Claudia Rella (University of Geneva)
    02/09/2024, 15:10
    Resurgence and non-perturbative methods 1
    Talk in parallel session

    In this talk, I will present recent work on the structure of wave functions in complex Chern-Simons theory on the complement of a hyperbolic knot in the three-sphere. The holomorphic blocks in the decomposition of the full non-perturbative wave function conjecturally possess a hidden integrality structure that guarantees the cancellation of potential singularities at rational points. The exact...

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  20. Canberk Sanli (CEICO, FZU Prague)
    02/09/2024, 15:10
    Formal QFT 1
    Talk in parallel session

    Conformal symmetry introduces two predominant complications into one dimensional sigma models by constraining the target space geometry to a cone. Namely, the naive spectrum of the corresponding quantum mechanics suffers from the noncompactness and singularity issues, thus rendering the Witten index an ill-defined object. We demonstrate how these challenges can be overcome by introducing a...

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  21. Shai Chester (imperial college london)
    03/09/2024, 14:00

    We combine supersymmetric localization with the numerical conformal bootstrap to non-perturbatively study 4d N=4 super-Yang-Mills (SYM) and 3d ABJM theory for all N and coupling, which is dual to string theory and M-theory, respectively. For N=4 SYM, are bound on the lowest dimension operator interpolates between weak coupling results for the Konishi operator, and strong coupling results for...

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  22. Tim Adamo
    03/09/2024, 14:00
    Talk in parallel session

    In four spacetime dimensions, the self-dual sectors of gauge theory and gravity have infinite-dimensional chiral symmetry algebras which live on the Riemann sphere. These play a crucial role in the celestial holography programme, enabling the bootstrap of all-order collinear expansions and underpinning the only known top-down constructions for asymptotically flat holography. In higher...

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  23. Michal P. Heller (Ghent University)
    03/09/2024, 14:00
    Holography (applied) 1
    Talk in parallel session

    Holographic entanglement entropy has significantly advanced our understanding of the emergence of spacetime and paved a way for other sharp geometric proxies of the bulk such as holographic complexity. In the course of the past two years, it was proposed that a promising complementary proxy of the bulk, sensitive in particular to the emergence of the bulk time, is given by an analytic...

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  24. Alice Luscher (University of Oxford)
    03/09/2024, 14:00
    Supergravity 1
    Talk in parallel session

    Equivariant localization is a powerful method for performing integrals using fixed point theorems.
    Recently it has been applied to compute various holographic observables in supergravity without the need for solving any of the supergravity field equations.
    In particular the on-shell action takes a prticularly simple form depending only on topological data.
    I will discuss applications of...

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  25. David Osten (University of Wroclaw)
    03/09/2024, 14:00
    Symmetries
    Talk in parallel session

    A novel classically integrable model is proposed. It is a deformation of the two-dimensional principal chiral model, embedded into a heterotic ฯƒ-model. This is inspired by the bosonic part of the heterotic ฯƒ-model and its recent Hamiltonian formulation of the heterotic ฯƒ-model in terms of O(d,d+n)-generalised geometry. Classical integrability is shown by construction of a Lax pair and a...

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  26. Arpit Das
    03/09/2024, 14:30
    Symmetries
    Talk in parallel session

    We propose a symmetry-resolved entanglement for categorical non-invertible generalized symmetries (CaT-SREE) in (1+1)-dimensional CFTs. The definition parallels that of group-like invertible symmetries employing the concept of symmetric boundary states with respect to a categorical symmetry. Our examination extends to rational CFTs, where the behavior of CaT-SREE mirrors that of group-like...

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  27. Sucheta Majumdar (Centre de Physique Thรฉorique, Marseille)
    03/09/2024, 14:30
    Holography (flat) 2
    Talk in parallel session

    Considering the simple case of 2D massless scalar fields in the light-cone formulation, we shall explore several subtleties that arise when setting up the canonical formulation on a single or on two intersecting null hyperplanes. Our analysis is particularly well-suited for a consistent treatment of zero modes, matching conditions (akin to the antipodal map for asymptotic symmetries), and...

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  28. Barak Gabai (EPFL)
    03/09/2024, 14:30
    Bootstrap (CFT, S-matrix) 2
    Talk in parallel session

    Matrix QM bootstrap is a method which utilizes the equations of motion together with norm positivity to allow for a numerical determination of moments to high precision. I will cover the general pronciples and some of the recent advances. Particularly, I will explain how to extend the bootstrap to finite temperature and present comparisons to analytic methods.

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  29. Oscar Henriksson (ร…bo Akademi University)
    03/09/2024, 14:30
    Holography (applied) 1
    Talk in parallel session

    First-order phase transitions are somewhat neglected by theorists in favor of their second-order counterparts. Yet they contain rich physics, and are of importance in everything from condensed matter physics to (perhaps) early-universe cosmology.

    I will discuss the dynamics of first-order transitions at strong coupling, using holographic duality. First, I describe how to construct effective...

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  30. Alexia Nix (University of Iceland)
    03/09/2024, 14:30
    Supergravity 1
    Talk in parallel session

    In this talk, I will focus on the study of 1/2-BPS Wilson loop operators in maximally supersymmetric Yang Mills theories on (p+1)-dimensional spheres. The gravity duals to these theories are given by the backreacted geometry of spherical Dp-branes and our aim is to compute the holographic Wilson loops in these backgrounds up to next-to-leading order in the large โ€™t Hooft coupling expansion....

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  31. Marten Reehorst
    03/09/2024, 14:50
    Bootstrap (CFT, S-matrix) 2
    Talk in parallel session

    We study multiscalar theories with $\text{O}(N) \times \text{O}(2)$ symmetry. These models have a stable fixed point in $d$ dimensions if $N$ is greater than some critical value $N_c(d)$. The expectation is that at this critical value $N_c(d)$ a merger between the stable and unstable fixed point occurs and that for $N < N_c(d)$ the fixed points move off into the complex plane. Previous...

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  32. Gerben Oling (University of Edinburgh)
    03/09/2024, 14:50
    Holography (applied) 1
    Talk in parallel session

    While Carroll geometry has exciting applications in the context of flat space holography, we can also consider ultra-local Carroll limits in gravity itself. At first, this may seem like an esoteric thing to do, compared to for example the non-relativistic expansion of gravity. However, Carroll limits in GR turn out to give remarkable simplifications. In this talk, I will connect these limits...

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  33. Vasil Radoslavov Dimitrov (Unito Torino)
    03/09/2024, 14:50
    Supergravity 1
    Talk in parallel session

    Starting from [1810.11442][1] it was discovered that the dominant supersymmetric Euclidean AdS_5 black hole saddle is non-extremal (but complex, thus avoiding no-go theorems). If extremality is further imposed it becomes the standard supersymmetric and extremal (real) BPS saddle. At leading order in large N the thermodynamics of this saddle is recovered holographically by computing the...

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  34. Dr Bin Zhu (University of Edinburgh)
    03/09/2024, 14:50
    Holography (flat) 2
    Talk in parallel session

    It is shown that there exists a simple deformed version of Stromingerโ€™s infinite-dimensional w(1+infinity) algebra of soft graviton symmetries, which we conjecture to arise in spacetimes with a nonvanishing cosmological constant. The deformed algebra contains a subalgebra generating SO(1,4) or SO(2,3) symmetry groups of dS4 or AdS4, depending on the sign of the cosmological constant. The...

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  35. Mr Loukas Grimanellis (King's College London)
    03/09/2024, 14:50
    Symmetries
    Talk in parallel session

    It has been known that 2-dimensional supersymmetric sigma models admit symmetries generated by covariantly constant forms. For target spaces manifolds $M^n$ whose holonomy is included in $U(\frac{n}{2})$, $SU(\frac{n}{2})$, $Sp(\frac{n}{4})$, $Sp(\frac{n}{4}) \cdot Sp(1)$, $G_2 (n=7)$ and Spin(7)$(n=8)$, these symmetries close as a W-algebra. In heterotic sigma models, these symmetries are...

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  36. Nejc ฤŒeplak (Trinity College Dublin)
    03/09/2024, 15:10
    Holography (applied) 1
    Talk in parallel session

    Eternal asymptotically AdS black holes are dual to thermofield double states in the boundary CFT. It has long been known that black hole singularities have certain signatures in boundary thermal two-point functions related to null geodesics bouncing off the singularities (bouncing geodesics). In this talk I will discuss the manifestations of black hole singularities in the dual CFT.

    By...

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  37. Tobias Hansen (Durham University)
    03/09/2024, 15:10
    Bootstrap (CFT, S-matrix) 2
    Talk in parallel session

    I will present the derivation of the AdS Veneziano amplitude for the scattering of gluons in type IIB string theory on AdS5ร—S5/Z2โ€‹ in the presence of D7 branes, in a small curvature expansion. This is achieved by combining a dispersion relation in the dual 4d N=2 SCFT with an ansatz for the amplitude as an open string worldsheet integral over single-valued polylogarithmic functions evaluated...

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  38. Tancredi Schettini Gherardini (Queen Mary University of London)
    03/09/2024, 15:10
    Supergravity 1
    Talk in parallel session

    Exotic spheres are seven-dimensional, compact manifolds, which have been shown (through a non-constructive existence theorem) to admit numerous Sasaki-Einstein metrics. Hence, they are suitable candidates for compactifications of M-theory, but have never been considered in this context due to the lack of a suitable description. In this talk, I will discuss metrics on exotic spheres viewed as...

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  39. Mr Kevin Nguyen (Universitรฉ Libre de Bruxelles)
    03/09/2024, 15:10
    Holography (flat) 2
    Talk in parallel session

    I will present new progress in constructing a general operator product expansion for carrollian CFTs, and discuss its realization within carrollian correlation functions dual to massless scattering amplitudes. The establishment of a carrollian OPE is crucial to a bootstrap formulation of carrollian conformal field theory in general, and would appear primordial at a conceptual level as well as...

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  40. Francisco Reyes (Universidad de Santiago de Chile)
    03/09/2024, 15:10
    Symmetries
    Talk in parallel session

    The novel connection between the asymptotic dynamics of 2+1 General Relativity with Integrable Systems has been studied recently due the possibility to explore holography beyond conformal symmetry. In this regard, we construct a set of suitable boundary conditions for the gravitational field which deforms those of Brown-Henneaux using negative powers of the central charge. Through a recursive...

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  41. Sangmin Choi (University of Amsterdam)
    04/09/2024, 11:00
    Holography (flat) 2
    Talk in parallel session

    In the last few years, a remarkable link has been established between the soft theorems and asymptotic symmetries of quantum field theories: soft theorems are Ward identities of the asymptotic symmetry generators. In particular, the tree-level subleading soft theorems are the Ward identities of the subleading asymptotic symmetries of the theory, for instance divergent gauge transformation in...

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  42. Julian Sonner (Universite de Geneve (CH))
    04/09/2024, 11:00
    Talk in parallel session
  43. Ivano Basile (LMU)
    04/09/2024, 11:00
    String phenomenology and the swampland
    Talk in parallel session

    Towers of light states are ubiquituous in string theory, either due to excitations of the fundamental string or Kaluza-Klein excitations of (dually) large internal spaces. Does this picture hold in non-geometric phases? Via worldsheet methods, I will present some recent results to the effect that it does.

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  44. Massimo Taronna (University of Naples Federico II and INFN)
    04/09/2024, 11:00
    Talk in parallel session

    In this talk I will review recent efforts to put holographic correlators in maximally symmetric space-times on the same footings, upon analytic continuation to Euclidean AdS space. I will focus mainly on the dS example which played a key role for Cosmological Bootstrap. I will discuss in detail the analytic continuation introduced and how this continuation imply a map between perturbative...

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  45. Oliver Schlotterer (Uppsala University)
    04/09/2024, 11:00
    Talk in parallel session

    In this talk, multiloop string amplitudes are discussed as a rewarding laboratory to develop integration techniques on higher-genus Riemann surfaces. I will review a string-amplitude inspired generalization of the Brown-Levin elliptic polylogarithms and their Kronecker-Eisenstein integration kernels to arbitrary genus. The key ingredients are convolutions of Arakelov Green functions on genus-g...

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  46. Arvind Shekar (University of Southampton)
    04/09/2024, 11:30
    Black holes and quantum information 2
    Talk in parallel session

    Entanglement entropy quantifies the degree of entanglement between two quantum systems or between two subregions in a QFT and hence is an important tool to understand the quantum system. Certain tricks (Replica) and holographic duals (Ryu-Takayanagi Area) have been used to calculate this measure. However, its study in dimensions > 2 has been mostly limited to flat backgrounds and CFT vacuum...

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  47. ARTHUR,ELIAS LIPSTEIN (Durham University)
    04/09/2024, 11:30
    Cosmological amplitudes / cosmological bootstrap
    Talk in parallel session

    Cosmological observations suggest that the early universe was approximately described by a de Sitter geometry. In this background, the natural observables are in-in correlators, which can be computed by squaring the wavefunction of the Universe. Surprisingly, it turns out that in-in correlators are often much simpler than wavefunction coefficients and are closely related to scattering...

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  48. Yixuan Li (MPI Munich)
    04/09/2024, 11:30
    String phenomenology and the swampland
    Talk in parallel session

    Flux compactifications that give three- or four-dimensional Anti-de-Sitter vacua with a parametrically-small negative cosmological constant are supposed to be ubiquitous in String Theory. However, the 1+1 and 2+1 dimensional CFT duals to such vacua should have a very large central charges and rather unusual spectra. Furthermore, there are various swampland conjectures that such vacua should...

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  49. Shreyansh Agrawal
    04/09/2024, 11:30
    Holography (flat) 2
    Talk in parallel session

    The study of infrared structure of gauge and gravity theories has gained renewed interest in recent years. This was possible after the seminal works of Strominger et al. unraveling relations between the so-called soft theorems and asymptotic symmetries. For the case of gravity theory, these relations also helped pave the way for celestial holography. In the last decade, these relations have...

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  50. Shun-qing Zhang
    04/09/2024, 11:30
    Amplitudes (string theory, field theory, gravity)
    Talk in parallel session

    Integrated correlator of four superconformal stress-tensor primaries in $SU(N)$ $\mathcal{N}=4$ super Yang-Mills (SYM) theory in the perturbative limit takes a remarkably simple form, where the $L$-loop coefficient is given by a rational multiple of $\zeta(2L+1)$. In this talk, we extend the previous analysis of expressing the perturbative integrated correlator as a linear combination of...

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  51. Andrzej Pokraka
    04/09/2024, 11:50
    Amplitudes (string theory, field theory, gravity)
    Talk in parallel session

    We study the twisted (co)homology of a family of genus-one integrals โ€” the so called Riemann-Wirtinger integrals. These integrals are closely related to one-loop string amplitudes in chiral splitting where one leaves the loop-momentum, modulus and all but one puncture un-integrated. While not actual one-loop string integrals, they share many properties and are simple enough that the associated...

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  52. Sadra Jazayeri (Imperial College London)
    04/09/2024, 11:50

    In this talk, I introduce a novel relationship between cosmological correlators and flat space Feynman diagrams in momentum space. Focusing on Witten diagrams in de Sitter space with heavy internal lines and light external legs, I introduce the Massive Flat Space (MFS) limit. In this limit, (i) the external energies entering the bulk-to-boundary propagators are sent to zero, (ii) the mass of...

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  53. Piotr Tourkine (CNRS, LAPTh, Annecy)
    04/09/2024, 11:50
    Holography (flat) 1
    Talk in parallel session

    Celestial scattering amplitudes for massless particles are Mellin transforms of momentum-space scattering amplitudes with respect to the energies of the external particles, and behave as conformal correlators on the celestial sphere. However, there are few explicit cases of well-defined celestial amplitudes, particularly for gravitational theories: the mixing between low- and high-energy...

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  54. Chen-Te Ma (Iowa State University)
    04/09/2024, 11:50
    Black holes and quantum information 2
    Talk in parallel session

    We model backreaction in AdS$_2$ JT gravity via a proposed boundary dual Sachdev-Ye-Kitaev quantum dot coupled to Dirac fermion matter and study it from the perspective of quantum entanglement and chaos. The boundary effective action accounts for the backreaction through a linear coupling of the Dirac fermions to the Gaussian-random two-body Majorana interaction term in the low-energy limit....

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  55. Colin Yannick P Sterckx
    04/09/2024, 11:50
    Supergravity 2
    Talk in parallel session

    Exceptional Field Theory provides a natural framework to study compactification of 10/11D maximal supergravities. This tool allowed us to build new AdS$_4$ solutions by providing consistent truncations of Type IIB supergravity to $\mathcal{N}=8$ $D=4$ gauged supergravities. In this talk, we will review some AdS$_4 \times S^1 \times S^5$ solutions of Type IIB supergravity called โ€œS-foldsโ€ as...

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  56. Sergio Luigi Cacciatori (Universitร  degli Studi dell'Insubria, Department of Science and High Technology)
    04/09/2024, 12:10
    Cosmological amplitudes / cosmological bootstrap
    Talk in parallel session

    After recalling the role of the topology of the de Sitter and anti de Sitter manifold in determining the main properties of Quantum Field Theories on such backgrounds, we will show how space configuration calculations allow to compute loop integrals in such maximally symmetric spacetimes. In particular, we will show how a remarkable Kรคllรฉn-Lehmann formula allows to compute banana integrals up...

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  57. Giuseppe Bogna
    04/09/2024, 12:10
    Holography (flat) 1
    Talk in parallel session

    I will present the construction of tree-level amplitudes and chiral algebras around curved gauge theory backgrounds and space-times. Gluon two-point amplitudes around a self-dual dyon and graviton two-point amplitudes around self-dual Taub-NUT can be constructed by direct integration of the classical action. Twistor methods allow to extend the construction for MHV amplitudes at all...

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  58. Marius Gerbershagen
    04/09/2024, 12:10
    Black holes and quantum information 2
    Talk in parallel session

    We introduce a generalized entanglement entropy, known as entwinement, in 2d CFTs measuring entanglement between non-spatially organized degrees of freedom. Its holographic dual is at leading order given by the area of codimension two surfaces winding around black hole horizons or naked singularities. We study bulk quantum corrections to this formula, generalizing results by Faulkner,...

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  59. Filippo Revello (Utrecht University)
    04/09/2024, 12:10
    String phenomenology and the swampland
    Talk in parallel session

    A cornerstone of the Swampland program is the Swampland Distance Conjecture (SDC), which postulates the appearance of (exponentially) light towers of states when approaching infinite distance points in moduli space. As such, the conjecture is formulated for adiabatic field displacements, corresponding to trajectories along a geodesic. However, realistic cosmological applications involve...

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  60. Mr Hynek Paul (KU Leuven)
    04/09/2024, 12:10
    Amplitudes (string theory, field theory, gravity)
    Talk in parallel session

    Despite recent progress in the evaluation of 4pt string amplitudes, not much is known about the coefficients in their low energy expansion beyond genus 1. I will describe a simple method, based on the partial-wave decomposition of the tree-level amplitude, which predicts the leading logarithmic discontinuity at any order in \alpha' and any genus. Based on WIP with Yu-tin Huang and Michele Santagata.

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  61. Viktor Gorbenko (EPFL - Ecole Polytechnique Federale Lausanne (CH))
    05/09/2024, 14:00
    Talk in parallel session

    We study a model for the initial state of the universe based on a gravitational path integral that includes connected geometries which simultaneously produce bra and ket of the wave function. We argue that a natural object to describe this state is the Wigner distribution, which is a function on a classical phase space obtained by a certain integral transform of the density matrix. We work...

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  62. Lakshya Bhardwaj
    05/09/2024, 14:00
    Talk in parallel session

    Landau's paradigm for understanding phase diagrams of quantum systems occupies a central place in theoretical physics. Quantum states are organised into phases characterized by patterns of spontaneous breaking of global symmetries. Despite its successes, severe limitations of this paradigm have been uncovered over the last decades with the discovery of an increasing number of phases of matter...

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  63. Alexander Tyukov (University of Southampton)
    05/09/2024, 14:00
    Holography
    Talk in parallel session

    We use the supergravity technique to compute heavy-heavy-light-light (HHLL) four-point correlation functions of operators in 4D N=4 Super Yang-Mills (SYM) theory. We compute the two-point function of light probe operators in the background of Lin-Lunin-Maldacena (LLM) geometries dual to heavy operators, thus avoiding the use of Witten diagrams. By taking a limit of the HHLL correlators, we...

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  64. Jelle Hartong (University of Edinburgh)
    05/09/2024, 14:00
    Talk in parallel session

    I will give an introduction to various non-Lorentzian geometries and their appearance in gravity and field theory. I will then make the case for the study of non-Lorentzian string theories both as limits of ordinary string theory and in their own right. This includes generalisations of the Gomis-Ooguri string (both open and closed) and non-relativistic strings that arise for example via...

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  65. Aaron Poole (Kyung Hee University)
    05/09/2024, 14:00
    Supergravity 2
    Talk in parallel session

    There has been recent interest in supergravity solutions which display the singularities of a particular 2-orbifold known as a "spindle". In this talk I will discuss the computation of the partition function of N = (2,2) SQFTs on the spindle via the technique of supersymmetric localization. I will explain how this background avoids the classes of 2-manifolds for which direct N = (2,2)...

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  66. Oliver Janssen (EPFL)
    05/09/2024, 14:30
    Cosmology (formal, string cosmology)
    Talk in parallel session

    A new axiom in QFT due to Kontsevich & Segal (https://arxiv.org/abs/2105.10161) which replaces the usual causality axiom by the requirement that the theory be well-defined on a special set of "allowable" complex metrics, has been suggested by Witten (https://arxiv.org/abs/2111.06514) to be elevated to a criterion in quantum gravity which distinguishes saddle points that could contribute to the...

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  67. Dr Alessio Fontanarossa (University of Turin)
    05/09/2024, 14:30
    Supergravity 2
    Talk in parallel session

    We construct $1/4$-BPS, asymptotically locally hyperbolic Euclidean solutions of $d=4$, $\mathcal{N}=2$ gauged supergravity, describing the total space of orbifold line bundles over a spindle. These $U(1) \times U(1)$-invariant solutions are divided into two classes, corresponding to either the twist or the anti-twist on the spindle-bolt, and generalize the spherical bolts found in...

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  68. Craig Lawrie
    05/09/2024, 14:30
    Generalised symmetries
    Talk in parallel session

    A (2k)-dimensional quantum field theory involving self-dual (k-1)-form gauge fields a priori defines a relative QFT; the partition function is not scalar-valued when evaluated on closed spacetime manifolds. It is necessary to pick a polarization of the intermediate defect group to have a well-defined, or absolute, QFT. Once the polarization is chosen the resulting theory has a (k-1)-form...

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  69. Mr Juan Hernandez (Vrije Universiteit Brussel)
    05/09/2024, 14:30
    Black holes and quantum information 1
    Talk in parallel session

    We study infinite families of black hole microstates consisting of wormholes and shells of matter. They are orthogonal at leading order in the saddle point approximation of the Euclidean gravitational path integral, suggesting a dramatic overcounting of the dimension of the microcanonical subspace. However, wormhole contributions in higher moments of the overlaps reveal small off-diagonal...

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  70. Stefano Baiguera (Ben-Gurion University of the Negev)
    05/09/2024, 14:30
    Non-relativistic field theories
    Talk in parallel session

    Spin Matrix Theories (SMTs) describe the near-BPS limit of $\mathcal{N}=4$ super Yang-Mills theory, which enables us to probe finite-N effects like D-branes and black hole physics. In the last years, we developed a systematic method to construct SMTs for various limits, including the largest possible case with PSU(1,2|3) invariance. This sector is particularly important because it admits dual...

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  71. Dr Adrita Chakraborty (AGH University of Science and Technology)
    05/09/2024, 14:50
    Non-relativistic field theories
    Talk in parallel session

    We explore connections between two salient chaotic features, namely Lyapunov exponent and butterfly velocity, for the class of asymptotically Lifshitz black hole background with arbitrary critical exponent by implementing three different holographic approaches, namely, entanglement wedge method, out of time-ordered correlators (OTOC) and pole-skipping. We present a comparative study where all...

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  72. Emanuele Panella
    05/09/2024, 14:50
    Cosmology (formal, string cosmology)
    Talk in parallel session

    In this talk, I will present methods to construct exact solution to the semiclassical back-reaction problem in (2+1)-dimensional asymptotically de Sitter spacetime within the formalism of braneworld holography. In particular, starting from an AdS$_4$ C-Metric, I will describe how to construct a black hole solution that localises on an end-of-the-world brane which. From the lower-dimensional...

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  73. Lea Bottini (University of Oxford)
    05/09/2024, 14:50
    Generalised symmetries
    Talk in parallel session

    Recently, the notion of symmetry has been vastly generalised, coming to include what are now known as categorical, or non-invertible symmetries. In this talk, I will present a framework to study gapped infra-red phases of theories that have such categorical symmetries, which relies on the so-called Symmetry Topological Field Theory (SymTFT). This is a (d+1)-dimensional topological theory...

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  74. Edoardo Colombo
    05/09/2024, 14:50
    Supergravity 2
    Talk in parallel session

    We present the first example of holographic matching between the index of a SCFT defined on an orbifold with conical singularities and the entropy of supersymmetric AdS black holes. The orbifold in question is the spindle, which is homeomorphic to the sphere but it has orbifold conical singularities at the poles. We show that the large-N limit of the 3d spindle index of holographic...

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  75. Avik Banerjee (University of Crete)
    05/09/2024, 14:50
    Holography
    Talk in parallel session

    In this talk, I will demonstrate that the solutions of three-dimensional gravity obtained by gluing two copies of a spacetime across a junction constituted of a tensile string are in one-to-one correspondence with the solutions of the Nambu-Goto equation in the same spacetime up to a finite number of rigid deformations. The non-linear Nambu-Goto equation satisfied by the average of the...

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  76. Andrea Fontanella (Trinity College Dublin)
    05/09/2024, 15:10
    Non-relativistic field theories
    Talk in parallel session

    Formulating holography in spacetimes obtained via a non-relativistic limit, the so-called Newton-Cartan geometries, is a challenging task that nevertheless gives us access to understanding holography in non-Anti de-Sitter spacetimes. In this talk, I will discuss a recently proposed correspondence between non-relativistic string theory in the String Newton-Cartan version of AdS$_5\times$S$^5$...

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  77. Victor Franken
    05/09/2024, 15:10
    Cosmology (formal, string cosmology)
    Talk in parallel session

    Considering two antipodal observers in de Sitter space, we illustrate how spacetime connectivity between the holographic screens located on the (stretched) horizons emerges from holographic entanglement. To do so, we construct a covariant holographic entanglement entropy prescription in de Sitter space, including quantum corrections. Entanglement wedge reconstruction implies an extension of...

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  78. Javier Subils (ICCUB - Universitat de Barcelona)
    05/09/2024, 15:10
    Holography
    Talk in parallel session

    I present a new mechanism to generate large curvatures in asymptotically AdS spaces, in rather generic boost invariant setups. On the gravity side, curvature invariants grow in an extended region of spacetime in the bulk. When their values hit Plank scale, the classical approximation breaks down and higher curvature corrections should be taken into account. On the gauge theory side, this...

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  79. Christian Copetti (Oxford)
    05/09/2024, 15:10
    Generalised symmetries
    Talk in parallel session

    We show that crossing symmetry of S-matrices is modified in certain theories with non-invertible symmetries or anomalies. Focusing on integrable flows to gapped phases in two dimensions, we find that S-matrices derived previously from the bootstrap approach are incompatible with non-invertible symmetries along the flow.
    We present various examples and show how the preserved non-invertible...

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  80. Mr Alfred Bovon (Lyon University)
    05/09/2024, 15:10
    Supergravity 2
    Talk in parallel session

    The BFSS proposal can be understood within the framework of gauge/gravity duality: the holographic dual of matrix theory is a compactification of M-theory in an SO(9)-symmetric pp-wave background. I will present the formalism of holographic renormalization for the matter-coupled two-dimensional maximal supergravity, with fluctuations around a D0-brane geometry. I will discuss the...

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  81. Prof. Christopher Beem (University of Oxford)
    06/09/2024, 14:00
    Talk in parallel session

    Four-dimensional N=2 superconformal field theories (SCFTs) give rise, via a cohomological construction, to associated vertex operator algebras (VOAs) that have been much investigated in the last decade. A notable feature of this construction is that for unitary parent SCFT, the VOA so realised is non-unitary. In this talk I will describe a novel structure present for these VOAs that encodes...

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  82. Costis Papageorgakis (Queen Mary University of London)
    06/09/2024, 14:00
    Talk in parallel session

    After a brief overview of some of the recent developments in the field of Machine Learning and AI, I will discuss the potential use of such techniques in theoretical High Energy Physics with special emphasis on Quantum Field Theory. I will demonstrate relevant concepts with a specific novel application of Neural Operators in the context of S-matrix theory.

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  83. Stefan Forste (Bonn University)
    06/09/2024, 14:00
    CFT
    Talk in parallel session

    My talk will be based on work done together with Hans Jockers, Joshua
    Kames-King, Alexandros Kanargias and Ida Zadeh. We consider toroidal
    Z2 orbifold CFT's. If the Z2 acts not on all directions simultaneously
    one distinguishes factorisable versus non-factorisable
    orbifolds. Their moduli spaces will be discussed. Expressions for
    averaged one loop partition functions will be given....

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  84. Dr Raffaele Marotta
    06/09/2024, 14:00
    Holography (flat) 3
    Talk in parallel session

    We analyse the flat limit of AdS using the momentum space CFT representation of correlators. We consider an effective field theory of complex massive spin-1 fields interacting with an abelian gauge field on an asymptotically Anti-de Sitter background and implement the holographic renormalization procedure to compute the boundary CFT 3-point function involving a conserved current and two...

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  85. Veronica Fantini (IHร‰S)
    06/09/2024, 14:00
    Resurgence and non-perturbative methods 2
    Talk in parallel session

    Quantizing the mirror curve to a toric Calabi-Yau threefold gives rise to quantum operators whose fermionic spectral traces produce factorially divergent formal power series in the Planck constant and its inverse. These are conjecturally captured by the Nekrasov-Shatashvili and standard topological string free energies, respectively, via the TS/ST correspondence. Building on the study by C....

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  86. Mr Samuel Crew (Imperial college)
    06/09/2024, 14:30
    Resurgence and non-perturbative methods 2
    Talk in parallel session

    Parametric resurgence plays an important role in the study of physical observables, as in most cases correlators will depend on multiple parameters (such as the coupling and gauge group). In this talk I will discuss recent work in algebraic examples of parametric resurgence. We discuss a simple example to elucidate the so-called higher order Stokes phenomena and discuss how a Borel inner-outer...

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  87. Nadia Flodgren
    06/09/2024, 14:30
    Formal QFT 1
    Talk in parallel session

    We apply our previously developed approach to marginal corrections in QFTs with multiple scalars, which shows that one-loop RG flows can be described in terms of a commutative but non-associative algebra, to various vector, matrix and tensor models in 4D. We show that the algebra can be used to identify the useful scalings of the couplings for taking the large $N$ limit.

    Using this method,...

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  88. Dr Evgeny Sobko (London Institute for Mathematical Sciences)
    06/09/2024, 14:30
    Machine learning and AI
    Talk in parallel session

    In my talk, I will introduce a novel AI-based approach to Integrable Models. I will demonstrate how neural networks can be employed to numerically solve the Yang-Baxter equation and discover new integrable spin-chains. The Hamiltonians of these spin-chains form projective varieties, and I will show how, by using the Boost operator construction for conserved charges, we derive their analytical...

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  89. JESUS CRUZ ROJAS (APCTP)
    06/09/2024, 14:30
    CFT
    Talk in parallel session

    We investigate the effect that a Chern-Simons term has on the phase diagram of quark matter at finite density and temperature. We carried out the complete fluctuation analysis of the chirally symmetric black hole phase of the bottom-up holographic model V-QCD which models the deconfined phase of QCD. We classify all fluctuations and therefore all quasi-normal modes.

    We also analyse the...

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  90. Karan Fernandes
    06/09/2024, 14:30
    Holography (flat) 3
    Talk in parallel session

    Scattering amplitudes can be recovered in the AdS/CFT correspondence from CFT correlation functions by taking an infinite radius limit of the AdS spacetime. In this talk, I will discuss the soft factorization of scattering amplitudes in this limit. We first use `classical soft theorems' to establish that soft photon and soft graviton factors involve inverse AdS radius corrections of the known...

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  91. Andrei Constantin
    06/09/2024, 14:50
    Machine learning and AI
    Talk in parallel session

    The talk will outline recent progress in identifying realistic models of particle physics in heterotic string theory, supported by several mathematical and computational advancements which include: analytic expressions for bundle valued cohomology dimensions on complex projective varieties, heuristic methods of discrete optimisation such as reinforcement learning and genetic algorithms, as...

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  92. Dr Rodolfo Panerai (University of Cologne)
    06/09/2024, 14:50
    Resurgence and non-perturbative methods 1
    Talk in parallel session

    In this talk, I will present the all-orders perturbative expansion of the partition function of 2d Yang-Mills on arbitrary closed surfaces around unstable instantons, i.e. higher critical points of the classical action. I will describe two approaches to this result: through resummation of the lattice partition function, and through non-standard supersymmetric localization. The result of...

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  93. Jingxiang Wu (University of Oxford)
    06/09/2024, 14:50
    Formal QFT 1
    Talk in parallel session

    We propose a correspondence between topological order in 2+1d and Seifert three-manifolds together with a choice of ADE gauge group $G$. Topological order in 2+1d is known to be characterized in terms of modular tensor categories (MTCs), and we thus propose a relation between MTCs and Seifert three-manifolds. The correspondence defines for every Seifert manifold and choice of $G$ a fusion...

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  94. Yuyu Mo (University of Edinburgh)
    06/09/2024, 14:50
    Holography (flat) 3
    Talk in parallel session

    We propose an algorithm to recursively bootstrap n-point gluon and graviton Mellin-Momentum amplitudes in (A)dS spacetime using only three-point amplitude. We discover that gluon amplitudes are simply determined by factorization for n โ‰ฅ 5. The same principle applies to n-point graviton amplitudes, but additional constraints such as flat space and soft limits are needed to fix contact terms....

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  95. Ms Pratyusha Chowdhury (University of Southampton)
    06/09/2024, 14:50
    CFT
    Talk in parallel session

    Conformal invariance implies strong constraints on the form of correlation functions of gauge invariant operators, and these correlators diverge when their conformal dimensions satisfy certain relations. These divergences and their renormalization has been understood up to three-point functions in general dimension, and for specific dimensions for holographic 4-point function in d=3. Going...

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  96. Costis Papageorgakis (Queen Mary University of London)
    06/09/2024, 15:10
    Bootstrap (CFT, S-matrix) 1
    Talk in parallel session

    I will discuss stochastic optimisation techniques for numerically solving the crossing equations within the conformal bootstrap programme. This approach is informed by the use of Reinforcement Learning algorithms. I will present results for a 1D line-defect CFT but also highlight its wider applicability.

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  97. Hassaan Saleem (SUNY Albany)
    06/09/2024, 15:10
    CFT
    Talk in parallel session

    There are many aspects of 2D conformal field theories where we have a good understanding and powerful tools in the rational (RCFT) case, but these don't always apply to non-rational CFTs. As a laboratory to study these distinctions, we revisit conformal boundary states in the compact free boson CFT. At radii which are irrational multiples of the self-dual radius, an exceptional set of boundary...

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  98. Ronnie Rodgers
    06/09/2024, 15:10
    Holography (flat) 3
    Talk in parallel session

    Celestial holography is the conjecture that scattering amplitudes in ($d$+2)-dimensional asymptotically flat spacetimes are dual to correlators of a $d$-dimensional conformal field theory, called the celestial CFT (CCFT). In CFT we can calculate sub-region entanglement Rรฉnyi entropies (EREs) from correlators of twist operators, via the replica trick. We argue that CCFT twist operators are...

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  99. Hyungrok Kim (University of Hertfordshire)
    06/09/2024, 15:10
    Formal QFT 1
    Talk in parallel session

    Symmetries underlie physics. Often, symmetries do not hold exactly but
    only "up to homotopy" (often synonymous with "on shell"), and this
    corresponds to the mathematical structure of homotopy algebras (e.g.
    Lโˆž-algebras). We explore some of the many instances where such structures appear, including colour-kinematics duality, holomorphic twists, the
    Keldysh-Schwinger formalism, and the...

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  100. Bercel Boldis (HUN-REN Wigner Research Centre for Physics, Budapest University of Technology and Economics)
    06/09/2024, 15:10
    Resurgence and non-perturbative methods 2
    Talk in parallel session

    A special class of observables in N=4 and N=2 SYM can be expressed as determinants of semi-infinite matrices. At strong coupling, the expansion of these observables are asymptotic. The perturbative coefficients was already determined in the literature. We have established a method to systematically calculate the non-perturbative part as well. It is based on the fact that the elements of the...

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