Contemporary Perspectives on Cosmology and Gravity

24 nov. 2025, 09:00 → 28 nov. 2025, 18:30 Europe/Paris

Institut Pascal

Christos Charmousis (IJCLAB CNRS), Eugeny Babichev (IJCLab), Karim Noui (IJCLab, Paris-Saclay), Masahide YAMAGUCHI (IBS CTPU-CGA), Mohammad Ali Gorji (Institute for Basic Science (IBS))

This workshop brings together leading specialists in cosmology and gravity from two regions of the world—France and South Korea, as well as experts from other parts of the world. French participation will include researchers from IJCLab and LUX, while the Korean side will be represented by the Cosmology, Gravity, and Astroparticle Physics Group of the Center for Theoretical Physics of the Universe (Institute for Basic Science).
The program is designed to highlight recent advances in cosmology and gravity through research talks, foster in-depth discussions, and encourage strong scientific exchange between participants.

Key topics include:
1. Theoretical models of modified gravity.
2. Black holes in General Relativity and beyond.
3. Cosmology in alternative theories of gravity.

Getting here: Information about the event venue and how to reach it can be found at the following link

The program is locally sponsored by state grants ANR's COSQUA and StronG as well as P2I-Graduate School Physique, ANR-11-IDEX-0003

 

lun. 24 novembre

Welcome and registration

1 Theories with Torsion and Nonmetricity: From cosmology to Astrophysics

Orateur: Sebastián Bahamonde (Institute for Basic Science)

12:00 Lunch - Buffet

Lunch

Working in groups on common projects

2 Imperfect dark matter with higher derivatives

Orateur: Mohammad Ali Gorji (Institute for Basic Science (IBS))

Working in groups on common projects

mar. 25 novembre

Working in groups on common projects

3 An extra-natrual mechanism of superheavy Kaluza-Klein particle production

Orateur: Yusuke Yamada (IBS CTPU-CGA)

12:00 Lunch

4 Colloquium: Analogue Gravity and its applications to water waves

Analogue Gravity is a transdisciplinary field that explores and exploits the mathematical correspondence between, on one hand, field propagation in curved spacetime, and on the other, wave propagation in laboratory-based systems. In the long-wavelength limit, where the microscopic particulate nature of matter is lost from view, this correspondence is exact: the system is analogous to a gravitational one, with a background flow engendering an effective spacetime metric that governs the behaviour of wave-like perturbations. Unruh [Phys. Rev. Lett. 46, 1351 (1981)] was the first to suggest a concrete use of this analogy: to experimentally investigate Hawking radiation from black holes, which occur when the flow passes from a subcritical region to a supercritical one. The analogy can thus bring certain gravitational phenomena, hidden from view by practical difficulties, into the realms of observational accessibility via lab-based experiments.

I will give an overview of Analogue Gravity and present some applications to the particular system of water waves, which is being studied at Institut Pprime near Poitiers.

Orateur: Scott Robertson (Institut Pprime / CNRS)

14:30 Coffee break

Working in groups on common projects

Happy working hour

mer. 26 novembre

Workshop: Morning Session - 3 talks

5 Non-Gaussianity of tensor induced density perturbations

Orateur: Pritha Bari (University of Padova)

6 non-Markovianity in stochastic inflation

Orateur: Tomotaka Kuroda (IBS-CTPU-CGA/Institute of Science Tokyo)

7 Decoherence of primordial perturbations in the view of a local observer

Orateur: Fumiya Sano (Institute of Science Tokyo / Institute for Basic Science)

11:15 Coffee break

Workshop: Morning session - 2 talks

8 Cosmological correlators beyond the de-Sitter lamppost

Orateur: Yuhang Zhu (IBS-CTPU-CGA)

9 Nonsingular Cosmologies in Horndeski Gravity

Orateur: Pavel Petrov (IBS CTPU CGA)

12:30 Lunch

lunch

10 Secondary Gravitational Waves in Modified Gravity

Orateur: Guillem Domenech (Leibniz University Hannover)

15:00 Coffee break

Workshop: Afternoon session - 3 talks

11 On the fate of explicit diffeomorphism violation in gravity

Orateur: Nils A. Nilsson (IBS CTPU-CGA)

12 Imprints of energy injection by compact dark stars during reionization

Orateur: Boris Betancourt (IBS-CTPU-CGA)

13 Termination of Superradiance from a Binary Companion

Orateur: Huiyu Zhu (Institute for Basic Science)

Working in groups on common projects

Dinner at Gramophone

jeu. 27 novembre

Workshop: Morning Session - 3 talks

14 Black holes as a laboratory for dark matter

Orateur: Qianhang Ding (Institute for Basic Science)

15 Slowly rotating black holes in scalar-tensor theories of gravity

Orateur: Hugo CANDAN (Observatoire de Paris / IJCLab)

16 Theoretical filters for shift-symmetric Horndeski gravities

Orateur: Theodoros Nakas (Institute for Basic Science, CTPU-CGA)

11:15 Coffee break

Workshop: Morning session - 2 talks

17 Post-Newtonian tidal effects in the gravitational waveform from binary inspirals in scalar-tensor theories

Orateur: Eve DONES (LUX - Observatoire de Paris)

18 Quantum Ghost

Orateur: Atabak Jalali (CEICO, FZU)

12:30 Lunch

lunch

19 On Testing General Relativity with Gravitational Waves and Neutron Stars

Orateur: Mark Hertzberg (Tufts University)

15:00 Coffee break

Workshop: Afternoon session - 3 talks

20 A Photon Cloud Induced from an Axion Cloud

Orateur: Zi-Yu Tang

21 Multimodal axion emissions from Abelian-Higgs cosmic strings

Orateur: Michiru Uwabo (IBS-CTPU-CGA)

22 Decay and lifetime of oscillons coupled to an external scalar field: Insights from instability band analysis

Orateur: Siyao Li (IBS CTPU-CGA/Institute of Science Tokyo)

Working in groups on common projects

ven. 28 novembre

Working in groups on common projects

Discussion session: Cosmology

Président de session: Masahide YAMAGUCHI (IBS CTPU-CGA)

12:00 Lunch

Discussion session: Black holes

Président de session: Jacopo Mazza

15:30 Coffee break

Working in groups on common projects