The holographic correspondence predicts that certain strongly coupled
quantum systems describe an emergent, higher-dimensional bulk spacetime
in which excitations enjoy local dynamics. We consider a general
holographic state dual to an asymptotically AdS bulk spacetime, and
study boundary correlation functions of local fields integrated against
wavepackets. We derive a factorization...
Computing the spectrum of the Laplace operator on a compact Riemannian manifold is a classic problem in mathematical physics. For this presentation, we consider the four-dimensional Einstein metric on the non-trivial $S^2-$bundle over $S^2$ discovered by Page. A pseudospectral method is used to approximate the spectrum of the scalar Laplacian. We show our numerical results match well with...
Frobenius algebras and Hopf algebras generalize algebras of functions and Lie groups/Lie algebras, respectively. Appropriate constructions involving these two types of algebras link together concepts from functional analysis with those from Lie theory. As quantum field theories often involve a mixture of analytic and algebraic structures (for instance, performing analysis on operator-valued...
Classical mechanics can be cast in a framework that represents observables as operators and states as vectors in some Hilbert space, as shown by Koopman and von Neumann. In such a formulation, noncommuting operators naturally arise and the question of their physical interpretation is relevant for understanding both classical and quantum mechanics. We describe a general map from ordinary...
We use simple spectral perturbation theory to show that the positive partial transpose property is stable under bounded perturbations of the Hamiltonian, for equilibrium states in infinite dimensions. The result holds provided the temperature is high enough, or equivalently, provided the perturbation is small enough.
In order to search for physics beyond the Standard Model at the precision frontier, it is sometimes essential to account for higher-order radiative corrections. We perform complete and detailed calculations of electroweak radiative corrections to parity-violating lepton scattering with a distinguishable target (electron-proton, muon-proton) up to Next-to-Next-to-Leading Order (NNLO) level...
Currently, the most precise extraction of the up-down quark mixing element $ V_{ud} $ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix comes from a handful of $ft$-value measurements for nuclear Fermi decays in light- and medium-mass nuclei. However, a complete extraction of $ V_{ud} $ from hadronic decays requires challenging theory determinations of hadronic-structure-dependent electroweak...
We investigate the impact of Vector-Like Quarks (VLQs) on rare B-decay processes. Our approach involves careful examination of VLQ contributions in light of the most recent lower mass limit set by direct search data at LHC. By employing both symbolic and numerical computations, we compare our theoretical produce predictions in agreement with the latest Belle-II results, covering more than 3...
The microphysical properties of Dark Matter (DM), such as its mass and coupling strength, are typically assumed to retain their vacuum values when considering DM behaviour at a range of scales. However, DM interactions in different astrophysical and cosmological environments may be impacted by the properties of the background which in turn can substantially affect both DM production and the...
Big Bang Nucleosynthesis (BBN) describes the very first nucleosynthesis in the universe. The nuclear network of BBN produces the lightest elements and explains their cosmic abundances. With precision abundance observations, BBN can probe the physics of the early universe and place limits on key cosmological parameters. These key parameters also leave their imprint in the cosmic microwave...
When two galaxies collide, the supermassive black holes located at their centers can form a binary pair. These extreme gravitational situation causes ripples in spacetime (called gravitational waves) that carry away significant energy and angular momentum so that the two black holes themselves eventually collide. During the in-spiral phase, the gravitational waves are measurable by current...
The Tolman–Ehrenfest criterion of thermal equilibrium for a static fluid in a static spacetime is generalized to stationary heat conduction with negligible backreaction, and then applied to Hawking radiation in the Schwarzschild–de Sitter geometry. The two horizons acting as thermostats remain in thermal equilibrium. The temperature of the radiation fluid interpolates between those of the two...
Gavitational instantons are complete, Ricci-flat Riemannian manifolds (M,g) characterized by their asymptotic behaviour. We will cosnider asymptotically locally Euclidean (ALE) (a quotient of Euclidean space) with quartic volume growth, and asymptotically locally flat (ALF) spaces with cubic volume growth (e.g. a circle bundle over R^3). Explicit examples can be constructed from known black...
In the AdS/CFT correspondence, a subregion of a conformal field theory (CFT) allows for the recovery of a corresponding subregion of the bulk gravity theory known as its entanglement wedge. In some cases, an entanglement wedge contains a locally but not globally minimal surface homologous to the CFT subregion, in which case it is said to contain a python's lunch. It has been proposed that...
It is widely anticipated that a quantized theory of gravity will admit quantum spacetime configurations that are described by a superposition of semiclassical spacetimes. However, in the absence of such a complete theory of quantum gravity, can we learn anything about how such states might behave?
In this talk, I will present a recent operational approach to this problem using a...
I will discuss a notion of topology “hidden” in Landau’s theory of phase transitions. When the order parameter comprises several components in the same irreducible representation of symmetry, it can possess a nontrivial topology and acquire a Berry phase under the variation of thermodynamic parameters. To illustrate this idea, I will focus on the superconducting phase transition of an...
We generalize the Momentum Average (MA) approximation to compute the finite temperature spectral functions of the Holstein polaron in a one-dimensional system. We validate our MA results in 1D against available numerical data from density matrix renormalization group (DMRG) and the finite-temperature Lanczos method, establishing the accuracy of the MA results which are obtained at a...
The collapse of large-diameter, chiral, single-walled carbon nanotubes (SWCNTs) can form bilayer-like ribbons, characterized by quasi-one-dimensional (1D) moiré superlattices and exotic electronic behavior. Using analytical treatments of diameter, chirality, and moiré twist angles, we demonstrate that the moiré wavelength approximates the width of the collapsed SWCNT, producing quasi-1D moiré...
Quantum maps are central objects that allow the manipulation of quantum states and resources. However, not all maps are created equal, and some may be more valuable than others in performing certain resource conversions. For this reason, transforming a quantum map into another, possibly more desirable one, becomes a relevant and crucial task in quantum information processing. Such a...
A long-standing challenge in quantum error correction is the infeasibility of universal transversal gates, as shown by the Eastin- Knill theorem. We show that the Eastin-Knill no-go result is a special case that does not hold for a general error model and obtain a necessary and sufficient condition for a quantum error-correcting code to have universal transversal gates. Introducing a Lie...
First principles, or ab initio, nuclear theory describes atomic nuclei as systems of nucleons interacting by QCD-based chiral effective field theory (EFT) nucleon-nucleon and three-nucleon forces. In combination with chiral EFT electroweak currents, ab initio nuclear calculations can provide model-independent results with quantifiable uncertainties relevant for precision electroweak physics....
Traditional pairing in nuclear systems is of the identical-particle kind (i.e., neutron-neutron or proton-proton). This is counter-intuitive, given that the neutron-proton interaction is stronger. In earlier work, we had hypothesized that such neutron-proton pairing may appear in heavy nuclei. Such studies had assumed spherical symmetry, which is known to be an inappropriate assumption in this...
As standalone detections or in the context of multi-messenger signals, neutrinos offer opportunities to understand our universe in unprecedented ways. Their weakly interacting nature provides information about, among others, binary neutron star mergers. Interpreting neutrino observations from compact objects relies on models of neutrino emission and the still not fully understood nuclear...
Ultra-relativistic heavy-ions collisions performed at the Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC) produce a deconfined state of quarks and gluons, called the quark-gluon plasma (QGP). One of the primary goals of these collisions is to infer the properties of the QGP through the modifications it imparts on the evolution of high-energy quarks and gluons (also...
Upper year theoretical physics courses are conventionally delivered in a strict didactic form, where the instructor delivers 3 independent hour-long lectures per week. In the didactic method, students are left to work through the related highly complex and lengthy derivations independently. The degree to which these are assessed varies as they are difficult to incorporate into standard...
Scalable, fault-tolerant quantum computing depends on the development of efficient quantum error correction codes. While many good quantum low-density parity-check (qLDPC) codes have been introduced, there is still potential to discover better ones, particularly for small numbers of qubits relevant to the current era of noisy intermediate-scale quantum devices. This research systematically...
Despite the development in Engineering, the structure such as bridge continue to collapse due to fluid loads effects. Their combination on a bridge pier can also induced catastrophic damages. Less attention in literature has been given to bridge pier dynamics under transversal flow. This work describes the dynamic vibration, including theoretical non-linear dynamics analysis, of a bridge pier...
