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相关论文: Fermi-bounce cosmology and the fermion curvaton me…

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We develop a non-singular bouncing cosmology using a non-trivial coupling of general relativity to fermionic fields. The usual Big Bang singularity is avoided thanks to a negative energy density contribution from the fermions. Our theory is…

广义相对论与量子宇宙学 · 物理学 2014-12-10 Stephon Alexander , Cosimo Bambi , Antonino Marciano , Leonardo Modesto

Assuming the existence of a scalar field which undergoes "ghost condensation" and which has a suitably chosen potential, it is possible to obtain a non-singular bouncing cosmology in the presence of regular matter and radiation. The…

高能物理 - 理论 · 物理学 2011-04-20 Chunshan Lin , Robert H. Brandenberger , Laurence Perreault Levasseur

Cuscuton Gravity is characterized as a scalar field that can be added to general relativity without introducing any new dynamical degrees of freedom on a cosmological background. Yet, it modifies gravity such that spacetime singularities…

高能物理 - 理论 · 物理学 2025-05-19 Amir Dehghani , Ghazal Geshnizjani , Jerome Quintin

Within the context of the Fermi-bounce curvaton mechanism, we analyze the one-loop radiative corrections to the four fermion interaction, generated by the non-dynamical torsion field in the Einstein-Cartan-Holst-Sciama-Kibble theory. We…

广义相对论与量子宇宙学 · 物理学 2018-10-15 Andrea Addazi , Antonino Marciano

A bouncing scenario of a flat homogeneous and isotropic universe is explored by using the reconstruction technique for the power-law parametrization of the Hubble parameter in a modified gravity theory with higher-order curvature and trace…

广义相对论与量子宇宙学 · 物理学 2023-04-03 J. K. Singh , Harshna Balhara , Kazuharu Bamba , J. Jena

In this paper, we first introduce a multi-field setup of Cuscuton gravity in a curved field space manifold. Then, we show that this model allows for a regular bouncing cosmology and it does not lead to ghosts or other instabilities at the…

广义相对论与量子宇宙学 · 物理学 2023-01-25 Seyed Ali Hosseini Mansoori , Zahra Molaee

We show that it is possible for fermion condensation of the Nambu-Jona-Lasinio type to induce a non-singular bounce that smoothly connects a phase of slow contraction to a phase of expansion. A chiral condensate -- a non-zero vacuum…

广义相对论与量子宇宙学 · 物理学 2023-08-30 Giorgi Tukhashvili , Paul J. Steinhardt

We construct an asymmetric bouncing scenario within the VCDM model - also known as type-II minimally modified gravity -, a modified gravity theory with two local physical degrees of freedom. The scenario is exempt of any ghost or gradient…

广义相对论与量子宇宙学 · 物理学 2023-04-28 Alexander Ganz , Paul Martens , Shinji Mukohyama , Ryo Namba

The main objective of this manuscript is to investigate the bouncing cosmology in the background of $f(\mathcal{Q})$ gravity, where $\mathcal{Q}$ defines the non-metricity. For this purpose, we use the reconstruction approach and consider a…

广义相对论与量子宇宙学 · 物理学 2024-04-02 M. Sharif , M. Zeeshan Gul , Nusrat Fatima

A non-singular bouncing cosmology is generically obtained in loop quantum cosmology due to non-perturbative quantum gravity effects. A similar picture can be achieved in standard general relativity in the presence of a scalar field with a…

广义相对论与量子宇宙学 · 物理学 2014-03-17 Yi-Fu Cai , Edward Wilson-Ewing

We provide a novel mechanism that resolves the Big Bang Singularity present in FRW space-times without the need for ghost fields. Building on the fact that a four-fermion interaction arises in General Relativity when fermions are…

高能物理 - 理论 · 物理学 2009-09-02 Stephon Alexander , Tirthabir Biswas

We examine non-singular bounce cosmology within the framework of a phantom scalar field coupled to the Gauss-Bonnet term in both non-viscous and bulk-viscous cases. Using the scale factor ansatz…

宇宙学与河外天体物理 · 物理学 2026-05-07 Khandro K. Chokyi , Surajit Chattopadhyay

We consider a Bardeen-Cooper-Schrieffer (BCS)-like model in the inflationary background. We show that with an axial chemical potential, the attractive quartic fermion self-interaction can lead to a BCS-like condensation. In the rigid-de…

高能物理 - 理论 · 物理学 2024-06-11 Xi Tong , Yi Wang , Chen Zhang , Yuhang Zhu

We investigate a bounce realization in the framework of higher order curvature in $ f(R,T) $ modified theory of gravity. We perform a detailed analysis of the cosmological parameters to explain the contraction phase, the bounce phase, and…

广义相对论与量子宇宙学 · 物理学 2023-07-19 J. K. Singh , Shaily , Akanksha Singh , Aroonkumar Beesham , Hamid Shabani

The bouncing cosmology provides a successful solution of the cosmological singularity problem. In this paper, we study the bouncing behavior of a single scalar field model with tachyon field non-minimally coupled to itself, its derivative…

广义相对论与量子宇宙学 · 物理学 2015-06-03 A. Banijamali , B. Fazlpour

Cosmological inflation is a popular paradigm for understanding Cosmic Microwave Background Radiation (CMBR); however, it faces many conceptual challenges. An alternative mechanism to inflation for generating an almost scale-invariant…

宇宙学与河外天体物理 · 物理学 2024-07-24 S. Mahesh Chandran , S. Shankaranarayanan

Bouncing models of cosmology, as they arise e.g. in loop quantum cosmology, can be followed by an inflationary phase and generate close-to-scale-invariant fluctuation spectra as observed in the Cosmic Microwave Background (CMB). However,…

宇宙学与河外天体物理 · 物理学 2023-05-12 Bartjan van Tent , Paola C. M. Delgado , Ruth Durrer

In the present work, we study the cosmological model with fermionic field and with the non-canonical kinetic term (f-essence). We also present some important reductions of the model as well as its some generalizations. We also found the…

宇宙学与河外天体物理 · 物理学 2016-02-10 Ratbay Myrzakulov

We consider the introduction of anisotropy in a class of bouncing models of cosmology. The presence of anisotropy often spells doom on bouncing models, since the energy density due to the anisotropic stress outweighs that of other matter…

广义相对论与量子宇宙学 · 物理学 2022-01-27 Karthik Rajeev , Vikramaditya Mondal , Sumanta Chakraborty

An oscillating universe cycles through a series of expansions and contractions. We propose a model in which ``phantom'' energy with $p < -\rho$ grows rapidly and dominates the late-time expanding phase. The universe's energy density is so…

天体物理学 · 物理学 2014-10-13 Matthew G. Brown , Katherine Freese , William H. Kinney
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