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Related papers: Testing and Emulating Modified Gravity on Cosmolog…

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We propose a novel technique to refine the modelling of galaxy clusters mass distribution using gravitational lensing. The idea is to combine the strengths of both "parametric" and "non-parametric" methods to improve the quality of the fit.…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Eric Jullo , Jean-Paul Kneib

In this work, we provide an efficient and realistic data-driven approach to simulate astronomical images using deep generative models from machine learning. Our solution is based on a variant of the generative adversarial network (GAN) with…

Machine Learning · Computer Science 2019-09-27 Mohamad Dia , Elodie Savary , Martin Melchior , Frederic Courbin

As the next generation of large galaxy surveys come online, it is becoming increasingly important to develop and understand the machine learning tools that analyze big astronomical data. Neural networks are powerful and capable of probing…

In this talk we discuss some of the main theoretical problems in the understanding of the statistical properties of gravity. By means of N-body simulations we approach the problem of understanding the r\^ole of gravity in the clustering of…

Statistical Mechanics · Physics 2009-11-07 M. Bottaccio , R. Capuzzo Dolcetta , P. Miocchi , A. Amici , M. Montuori , L. Pietronero

We consider different observational effects to test modified gravity approach involving the cosmological constant in the common description of the dark matter and the dark energy. We obtain upper limits for the cosmological constant by…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 A. Amekhyan , S. Sargsyan , A. Stepanian

Upcoming Large Scale Structure surveys aim to achieve an unprecedented level of precision in measuring galaxy clustering. However, accurately modeling these statistics may require theoretical templates that go beyond second-order…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 M. Icaza-Lizaola , Yong-Seon Song , Minji Oh , Yi Zheng

Modified gravity (MG) theories aim to reproduce the observed acceleration of the Universe by reducing the dark sector while simultaneously recovering General Relativity (GR) within dense environments. Void studies appear to be a suitable…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-27 E L D Perico , R Voivodic , M Lima , D F Mota

We present $\texttt{MG-evolution}$, an $N$-body code simulating the cosmological structure formation for parametrised modifications of gravity. It is built from the combination of parametrised linear theory with a parametrisation of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-03 Farbod Hassani , Lucas Lombriser

We provide a cosmological test of modified gravity with two tensorial degrees of freedom and no extra propagating scalar mode. The theory of gravity we consider admits a cosmological model that is indistinguishable from the $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-01 Takashi Hiramatsu , Tsutomu Kobayashi

We present a convolutional neural network to classify distinct cosmological scenarios based on the statistically similar weak-lensing maps they generate. Modified gravity (MG) models that include massive neutrinos can mimic the standard…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Austin Peel , Florian Lalande , Jean-Luc Starck , Valeria Pettorino , Julian Merten , Carlo Giocoli , Massimo Meneghetti , Marco Baldi

There has been a lot of research interest in modified gravity theories which utilise the Vainshtein mechanism to recover standard general relativity in regions with high matter density, such as the Dvali-Gabadadze-Porrati and Galileon…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-24 Baojiu Li , Gong-Bo Zhao , Kazuya Koyama

Modifications to General Relativity (GR) often incorporate screening mechanisms in order to remain compatible with existing tests of gravity. The screening is less efficient in underdense regions, which suggests that cosmic voids can be a…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Christopher T. Davies , Marius Cautun , Baojiu Li

In the context of Chameleon gravity, we present a semi-analytical solution of the chameleon field profile in accurately modelled galaxy cluster's mass components, namely: the stellar mass of the Brightest Cluster Galaxy (BCG), the baryonic…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-04 Lorenzo Pizzuti , Valentina Amatori , Alexandre M. Pombo , Sandeep Haridasu

Modified gravity theories may provide an alternative to dark energy to explain cosmic acceleration. We argue that the observational program developed to test dark energy needs to be augmented to capture new tests of gravity on astrophysical…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Bhuvnesh Jain

We investigate clustering properties of dark matter halos and galaxies to search for optimal statistics and scales where possible departures from general relativity (GR) could be found. We use large N-body cosmological simulations to…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Jorge Enrique García-Farieta , Wojciech A. Hellwing , Suhani Gupta , Maciej Bilicki

Testing a subset of viable cosmological models beyond General Relativity (GR), with implications for cosmic acceleration and the Dark Energy associated with it, is within the reach of Rubin Observatory Legacy Survey of Space and Time (LSST)…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-16 Nesar Ramachandra , Georgios Valogiannis , Mustapha Ishak , Katrin Heitmann

Generative adversarial networks (GANs) were initially proposed to generate images by learning from a large number of samples. Recently, GANs have been used to emulate complex physical systems such as turbulent flows. However, a critical…

Computational Physics · Physics 2020-11-24 Zeng Yang , Jin-Long Wu , Heng Xiao

We introduce and demonstrate the power of a method to speed up current iterative techniques for N-body modified gravity simulations. Our method is based on the observation that the accuracy of the final result is not compromised if the…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-12 Alexandre Barreira , Sownak Bose , Baojiu Li

As cosmology rapidly approaches the data-dominated phase of stage IV large scale structure surveys, the modelling of nonlinear scales has become a serious challenge that faces the community, particularly when analysing models beyond $w$CDM.…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-14 Sankarshana Srinivasan , Shreya Prabhu , Kai Lehman , Ajiv Krishnan V. , Jochen Weller