CosmoFONDUE - Cosmological Fundamental Observables and Novel Discoveries in Universe Evolution

Session

Dark Energy and Modified Gravity

3B

12 Jun 2025, 11:30

Main auditorium (École de physique, Quai Ernest-Ansermet 24, 1205 Genève, Suisse)

77. Geometry and Gravity with non-linear clustering

Luca Amendola

12/06/2025, 11:30

Modified gravity

talk

Introduction to Dark Energy and Modified Gravity

A new avenue was recently developed for analyzing large-scale structure data which does not depend on assumptions about the power spectrum shape, the specific background
expansion, or the growth function.
In this talk I discuss how this model-independent methodology can be applied to answer three fundamental questions:
a) is space curve?;...

3. Thawing gravity and the cosmological tensions

Gen Ye (Leiden University)

12/06/2025, 12:00

Modified gravity

talk

It is found that the DESI observation can be explained by non-minimal coupled gravity. In this talk I will show that the resulting non-minimally coupled scalar-tensor gravity theory, Thawing Gravity (TG), also presents a possible resolution to the cosmological tensions. Using the standard Bayes model comparison method, TG has moderate evidence over $\Lambda$CDM with a Bayes factor $\ln B=+1.5$...

71. Field-level cosmological model selection: field-level simulation-based inference for Stage IV cosmic shear can distinguish dynamical dark energy

Alessio Spurio Mancini (Royal Holloway, University of London)

12/06/2025, 12:20

Modified gravity

talk

We present a framework that for the first time allows Bayesian model comparison to be performed for field-level inference of cosmological models. We achieve this by taking a simulation-based inference (SBI) approach using neural likelihood estimation, which we couple with the learned harmonic mean estimator in order to compute the Bayesian evidence for model comparison. We apply our framework...

6. Om and Statefinder Diagnostics of Anisotropic \( f(R, \mathcal{L}_m) \) Gravity

Dnyaneshwar Pawar (School of Mathematical Sciences Swami Ramanand Teerth Marathwada University, Vishnupuri, Nanded, India)

12/06/2025, 12:40

Modified gravity

talk

A locally rotationally symmetric Bianchi type-I model has been analyzed with a perfect fluid within the framework of ( f(R, \mathcal{L}_m) ) gravity. The exact field equations were derived, the variable deceleration parameter ( q(t) = \alpha - \frac{\beta}{H} ) has been used here. The cosmological parameters such as energy density, pressure, equation of state, spatial volume, the Hubble...

15. Observationally Constrained Bianchi-I Cosmology in \texorpdfstring{$f(Q,T)$}{f(Q,T)} Gravity with Two-Fluid Matter Sources

Basweshwar Jakore (Swami Ramanand Teerth Marathwada University Nanded Maharashtra)

Modified gravity

talk

\begin{abstract}
In this work, we investigate a cosmological model within the framework of ( f(Q,T) ) gravity, incorporating two-fluid dynamics composed of matter and radiation. The model is constructed using the anisotropic Bianchi type-I metric to explore the evolution of the universe in an extended gravitational theory where the non-metricity scalar ( Q ) is coupled with the trace of...