Zobrazeno 1 - 10
of 639
pro vyhledávání: '"83F05"'
Autor:
Goldstein, Piotr P.
A detailed description of the asymptotic behaviour in the Belinski-Khalatnikov-Lifshitz (BKL) scenario is presented through a simple geometric picture. The Lagrangian version of the dynamics governed by the BKL equations is described in terms of traj
Externí odkaz:
http://arxiv.org/abs/2411.07846
The recent fit of cosmological parameters by the Dark Energy Spectroscopic Instrument (DESI) collaboration will have a significant impact on our understanding of the universe. Given its importance, we conduct several consistency checks and draw concl
Externí odkaz:
http://arxiv.org/abs/2409.19577
Autor:
Franco-Grisales, Andrés
In a recent work, Ringstr\"om proposed a geometric notion of initial data on big bang singularities. Moreover, he conjectured that initial data on the singularity could be used to parameterize quiescent solutions to Einstein's equations; that is, rou
Externí odkaz:
http://arxiv.org/abs/2409.17065
Autor:
Maurya, Dinesh Chandra
In the present paper, we investigate constrained transit cosmological models in the most recent proposed modified gravity theory, $f(R,L_{m},T)$-gravity. We obtain the modified field equations for a flat homogeneous and isotropic Friedmann-Lema\^{\i}
Externí odkaz:
http://arxiv.org/abs/2409.14024
Autor:
Huang, Zhiqi, Ouyang, Xichang, Cui, Yu, Liu, Jianqi, Yao, Yanhong, Qiu, Zehong, Yu, Guangyao, Huang, Lu, Li, Zhuoyang, Wong, Chi-Fong
Preheating at the end of inflation is a violent nonlinear process that efficiently transfers the energy of the inflaton to a second field, the preheat field. When the preheat field is light during inflation and its background value modulates the preh
Externí odkaz:
http://arxiv.org/abs/2408.14881
In this manuscript, we put forth a general scheme for defining initial value problems from Einstein's equations of General Relativity constrained by homogeneous and isotropic expansion. The cosmological models arising as solutions are naturally inter
Externí odkaz:
http://arxiv.org/abs/2408.01644
Autor:
Yang, Yisong
Publikováno v:
Advanced Lectures in Mathematics, Volume 44, Proceedings of the Seventh International Congress of Chinese Mathematicians, Volume II, 2016 (ed. L. Ji, L. Yang, and S.-T. Tau), pp. 389--408, International Press, Boston and Beijing, 2019
The Einstein equations of general relativity reduce, when the spacetime metric is of the Friedmann--Lemaitre--Robertson--Walker type governing an isotropic and homogeneous universe, to the Friedmann equations, which is a set of nonlinear ordinary dif
Externí odkaz:
http://arxiv.org/abs/2407.19250
Autor:
Hassannejad, Ramin
The existence of fluctuations at the early stage of the universe provides enough confidence to rely on the averaging methods. However, the nonlinearity of general relativity makes it extremely difficult. There are different methods to study inhomogen
Externí odkaz:
http://arxiv.org/abs/2407.01506
We propose a new cosmological model that considers dark matter as a barotropic fluid with a constant equation of state parameter and interprets dark energy as the phenomenological emergent dark energy rather than a cosmological constant. This proposa
Externí odkaz:
http://arxiv.org/abs/2406.03936
Autor:
Huang, Zhiqi, Liu, Jianqi, Mo, Jianfeng, Su, Yan, Wang, Junchao, Yao, Yanhong, Yu, Guangyao, Zhu, Zhengxin, Li, Zhuoyang, Liu, Zhenjie, Miao, Haitao, Tong, Hui
Joint analysis of the baryon acoustic oscillations (BAO) measurement by the Dark Energy Spectroscopic Instrument (DESI) first data release, Type Ia supernovae (SNe) of the Dark Energy Survey Year 5 (DES5YR) release and cosmic microwave background (CM
Externí odkaz:
http://arxiv.org/abs/2405.03983