2026 Theory Canada 18

Session

Strings and Quantum Gravity

QG

19 Jun 2026, 14:00

A-4502.1 (Université de Montréal (MIL campus))

70. Charge conjugation symmetry and Monodromy defects in Cern-Simons theory

Dr Federico Ambrosino (Perimeter Institute)

19/06/2026, 14:00

Contributed Talk

In this talk, based on upcoming work with J. Gomis and S. Kannagi, I will discuss an important class of defects in Cern simons theory that implement charge conjugation symmetry. These are monodromy defects and, although some of their properties have been studied in N=4 SYM, we study them for the first time in the context of CS theory. Their quantum dimensions can be computed exactly as...

95. Origin of the SO(9)-> SO(3) x SO(6) symmetry breaking in the type IIB matrix model

Julia Pasiecznik (McGill University)

19/06/2026, 14:20

Strings and Quantum Gravity

Contributed Talk

We suggest a dynamical mechanism which explains why, in the supersymmetric Ishibashi-Kawai-Kitazawa-Tsuchiya matrix model, the $SO(9)$ symmetry of the Lagrangian is spontaneously broken to $SO(3) \times SO(6)$, allowing only three large classical spatial dimensions to emerge. The argument relies on the identification of D-strings as stable excitations of the matrices about the cosmological...

89. Higher symmetries and 4d quantum gravity

Florian Girelli (University of Waterloo)

19/06/2026, 14:40

Strings and Quantum Gravity

Contributed Talk

Topological (quantum) field theories are mathematically rich frameworks that rely on generalized symmetry structures, such as quantum groups in 3d and higher symmetries in 4d, to probe topological properties of manifolds. They also play a central role in quantum gravity. In 2d and 3d, gravity itself is a topological theory, while in 4d, gravitational dynamics can be obtained from suitable...

67. Stability of R-Charged Membranes

lucas Brown (University of Western Ontario)

20/06/2026, 09:45

Strings and Quantum Gravity

Contributed Talk

We address a correction to A.Buchel and R.Monten's analysis of near-extremal membranes in M-theory. The original authors consider the holographic dual of a $2+1$ dimensional superconformal gauge theory with $U(1)_R \times U(1)_B$ global symmetry. We repeat their analysis of R-charged membranes and identify a mistake; the charge transport is now stable and only the alternative quantization...

50. Static and axisymmetric black holes in improved GUP: theory and phenomenology

Prof. Saeed Rastgoo (University of Alberta)

20/06/2026, 10:05

Strings and Quantum Gravity

Contributed Talk

I will present a model of generalized uncertainty-inspired quantum black hole, both in the static and axisymmetric cases. By comparing the shadow of the axisymmetric version of this black hole to the data from the Event Horizon Telescope, I will set bounds on the quantum parameters of the model. Moreover, We will see that there is an upper bound on this black hole's spin parameter that is...

51. Relational Quantum Black Holes: Bounce and Singularity Resolution

Paolo Fragolino (University of Alberta)

20/06/2026, 10:25

Strings and Quantum Gravity

Contributed Talk

In this work, we examine the quantum properties of a Kantowski-Sachs minisuperspace through the lense of Dirac quantization and relational evolution. The relational dynamic is obtained thanks to the use of quantum clocks, which are built from one of the two degrees of freedom of the metric. Gauge-invariant extension of gauge-dependent observables are built relationally with respect to the...

77. On observers, fixed geometry states, and generalized entanglement wedges

Chris Waddell (Perimeter Institute)

20/06/2026, 16:00

Contributed Talk

We consider rules for modifying holographic tensor networks proposed in two independent contexts: by Akers et al. (CO) to incorporate observers in holographic maps, and by Kaya-Rath-Ritchie (KRR) to derive the Bousso-Penington generalized entanglement wedge proposal. Interestingly, these two sets of tensor network rules are exactly equivalent, KRR = CO. This suggests a more general connection...

92. Probing spacetime fluctuations with observables

Robin Oberfrank (Perimeter Institute)

20/06/2026, 16:20

Strings and Quantum Gravity

Contributed Talk

Can short-distance quantum fluctuations leave an imprint at large distances? This question is especially important in gravity, where high-energy physics may influence low-energy observables. In this talk, I will discuss this question using the time delay of light rays in interferometer setups as a concrete observable. I will present the gauge-invariant definition of the time-delay noise and...

60. Quantum Geometry from Commutators

Dr Vahid Kamali

20/06/2026, 16:40

Strings and Quantum Gravity

Contributed Talk

We propose a kinematical framework in which spacetime geometry is encoded directly in the Heisenberg commutators: the metric becomes an operator extracted from $[\,\hat x^\mu,\hat P_\nu\,]$, and the non-commutativity of translation generators follows from Jacobi closure. The construction naturally yields an operator analogue of metric compatibility and reproduces the familiar torsion/curvature...