2026 Theory Canada 18

Session

Gravitation and Cosmology

19 Jun 2026, 09:45

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

80. Conversion between Gravitational and Electromagnetic Waves at Medium Boundaries

Serge Hamoudou (McMaster University)

19/06/2026, 09:45

Relativity, Gravitation and Cosmology

Contributed Talk

It is well known that in the bulk of a background electromagnetic field, photons and gravitons convert into one another. This phenomenon is known as the Gertsenshtein effect. I use this result to examine what happens at a boundary separating a vacuum region from a background electromagnetic field, and I find that up to 34 % of an incoming gravitational wave's energy can get reflected and...

94. Polarization Formalism for Photon–Gravitational Wave Mixing Around Magnetars

Jean-Simon Côté (Université Laval)

19/06/2026, 10:05

Relativity, Gravitation and Cosmology

Contributed Talk

Gravitational-wave astronomy has opened a new observational window onto extreme astrophysical phenomena such as black-hole and neutron-star mergers. While current and next-generation interferometric detectors are primarily sensitive to the low-frequency regime, high-frequency gravitational waves (HFGWs) provide a promising probe of physics beyond the Standard Model, since no known conventional...

87. Cold and Fuzzy Dark Sector

Christian Capanelli (McGill University)

19/06/2026, 10:25

Relativity, Gravitation and Cosmology

Contributed Talk

In this talk, I will introduce the Fuzzy Dark Sector (FDS) scenario: a rich, interacting system and candidate for dark matter. This serves as a natural extension of the single-component, non-interacting Fuzzy Dark Matter (FDM) paradigm. Concretely, I will discuss an ultra-light Abelian-Higgs model, with interacting Higgs and dark photon degrees of freedom. In cosmology, the transfer function...

74. The 13CO(2–1)/12CO(2–1) Line Ratio from 100 Molecular Clouds in the Large Magellanic Cloud

Dia Kalra (University of Alberta)

20/06/2026, 09:45

Relativity, Gravitation and Cosmology

Contributed Talk

We analyze the line ratio of the 13CO(2–1) to 12CO(2–1) rotational transitions observed from new Atacama Large Millimeter/submillimeter Array observations of 100 Giant Molecular Clouds that span the Large Magellanic Cloud. We measure a median line ratio of 13CO(2–1)/12CO(2–1) = 0.078 with 68% of the sample falling between 0.058 and 0.107. A regression analysis confirms a nearly linear...

63. Dark Energy Bubble as Dynamical Dark Energy: Properties and CMB Constraints

Batia Friedman-Shaw

20/06/2026, 10:05

Relativity, Gravitation and Cosmology

Contributed Talk

Recent Dark Energy Spectroscopic Instrument (DESI) results have garnered attention from the cosmology community due to tension with the $\Lambda$CDM cosmological model when combined with cosmic microwave background (CMB) data. The tension suggests that a new model for dark energy may be warranted. Current alternative models focus mainly on a time-varying component of dark energy due in part to...

53. Unified Standard Model with Emergent Gravity-Effective Field Theory: First Successful Unification of Gravity with the Standard Model

Dr Farrukh Ahmed Chishtie

20/06/2026, 10:25

Strings and Quantum Gravity

Contributed Talk

I present the Unified Standard Model with Emergent Gravity-Effective Field Theory (USMEG-EFT), demonstrating for the first time a consistent unification of four-dimensional general relativity with the Standard Model within a fully renormalizable effective field theory framework. The approach employs a Lagrange multiplier field that enforces Einstein's equations at the path-integral level,...