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Related papers: Viable Mimetic $F(R)$ Gravity Compatible with Plan…

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We study mimetic $F(R)$ gravity with potential and Lagrange multiplier constraint. In the context of these theories, we introduce a reconstruction technique which enables us to realize arbitrary cosmologies, given the Hubble rate and an…

General Relativity and Quantum Cosmology · Physics 2016-02-17 S. D. Odintsov , V. K. Oikonomou

In this paper, we employ mimetic $f(R,T)$ gravity coupled with Lagrange multiplier and mimetic potential to yield viable inflationary cosmological solutions consistent with latest Planck and BICEP2/Keck Array data. We present here three…

General Relativity and Quantum Cosmology · Physics 2021-07-28 Snehasish Bhattacharjee

In the framework of the mimetic approach, we study the $f(R,R_{\mu\nu}R^{\mu\nu})$ gravity with the Lagrange multiplier constraint and the scalar potential. We introduce field equations for the discussed theory and overview their…

General Relativity and Quantum Cosmology · Physics 2021-11-18 Adam Zenon Kaczmarek , Dominik Szczęśniak

In this work, we extend the bottom-up reconstruction framework of $F(R)$ gravity to other modified gravities, and in particular for $f(\phi)R$ and mimetic $F(R)$ gravities. We investigate which are the important conditions in order for the…

General Relativity and Quantum Cosmology · Physics 2018-03-14 S. D. Odintsov , V. K. Oikonomou

We propose the mimetic $F(R)$ theory and investigate the early-time and late-time acceleration in such theory. It is demonstrated that inflation consistent with observable data may be realized in such theory. The reconstruction of realistic…

High Energy Physics - Theory · Physics 2014-12-19 Shin'ichi Nojiri , Sergei D. Odintsov

In this work we introduce and study the unimodular-mimetic $f(\mathcal{G})$ gravity, where unimodular and mimetic constraints are incorporated through corresponding Lagrange multipliers. We present field equations governing this theory and…

General Relativity and Quantum Cosmology · Physics 2023-11-13 Adam Z. Kaczmarek , Dominik Szczęśniak

In this paper we demonstrate that in the context of mimetic $F(R)$ gravity with Lagrange multiplier, it is possible to realize cosmologies which are compatible with the recent BICEP2/Keck Array data. We provide some characteristic examples…

General Relativity and Quantum Cosmology · Physics 2016-05-25 S. D. Odintsov , V. K. Oikonomou

We propose the unimodular-mimetic $F(R)$ gravity theory, to resolve cosmological constant problem and dark matter problem in a unified geometric manner. We demonstrate that such a theory naturally admits accelerating universe evolution.…

General Relativity and Quantum Cosmology · Physics 2016-06-29 S. D. Odintsov , V. K. Oikonomou

We extend the formalism of the Einstein-Hilbert unimodular gravity in the context of modified $F(R)$ gravity. After appropriately modifying the Friedmann-Robertson-Walker metric in a way that it becomes compatible to the unimodular…

General Relativity and Quantum Cosmology · Physics 2016-06-01 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

In this short review, we revisit inflation in F(R)-gravity. We find several F(R)-models for viable inflation by applying some reconstruction techniques. A special attention is payed in the reproduction of the last Planck satellite data. The…

General Relativity and Quantum Cosmology · Physics 2016-09-02 Lorenzo Sebastiani , Ratbay Myrzakulov

We investigate inflation in frames of two classes of $F(R)$ gravity and check its consistency with Planck data. It is shown that $F(R)$ inflation without self-reproduction may be constructed in close analogy with the corresponding scalar…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Shin'ichi Nojiri , Sergei D. Odintsov

A specific Horndeski scalar-gravity mimetic model is investigated within a FLWR space-time. The mimetic scalar field is implemented via a Lagrangian multiplier, and it is shown that the model has equations of motion formally similar to the…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Yevgeniya Rabochaya , Sergio Zerbini

We investigate the inflationary realization in the context of unimodular $F(T)$ gravity, which is based on the $F(T)$ modification of teleparallel gravity, in which one imposes the unimodular condition through the use of Lagrange…

General Relativity and Quantum Cosmology · Physics 2017-06-29 Kazuharu Bamba , Sergei D. Odintsov , Emmanuel N. Saridakis

We review on the viability of $F(R)$-gravity. We show that recent cosmic acceleration, radiation/matter-dominated epoch and inflation could be realized in the framework of $F(R)$-gravity in the unified way. For some classes of…

Astrophysics · Physics 2008-02-01 Shin'ichi Nojiri , Sergei D. Odintsov

In this paper, we demonstrate that a unified description of early and late-time acceleration is possible in the context of mimetic $F(R)$ gravity. We study the inflationary era in detail and demonstrate that it can be realized even in…

General Relativity and Quantum Cosmology · Physics 2016-12-21 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

In this paper, we consider an inflationary model of $f(R)$ gravity with polynomial form plus logarithmic term. We calculate some cosmological parameters and compare our results with the Plank 2015 data. We find that presence of both…

General Relativity and Quantum Cosmology · Physics 2016-06-14 J. Sadeghi , B. Pourhassan , A. S. Kubeka , M. Rostami

In this paper, we study a theory of gravity called mimetic $f(R, T)$ in the presence of swampland dS conjecture. For this purpose, we introduce several inflation solutions of the Hubble parameter H(N) from $f(R, T)= R+\delta T$ gravity…

General Relativity and Quantum Cosmology · Physics 2022-08-26 S. Noori Gashti , J. Sadeghi , S. Upadhyay , M. R. Alipour

We investigate the cosmic inflation scenario of a specific $f(R)$ model that contains more than one higher-order term in $R$. The $f(R)$ considered here has the terms $R^2$, $R^3$, and $R^4$ along with the linear term. A rigorous…

General Relativity and Quantum Cosmology · Physics 2022-11-16 Sahazada Aziz , Sohan Kumar Jha , Anisur Rahaman

We investigate inflation within $f(R,\phi)$-theories, where a dynamical scalar field is coupled to gravity. A class of models which can support early-time acceleration with the emerging of an effective cosmological constant at high…

General Relativity and Quantum Cosmology · Physics 2018-12-13 R. Myrzakulov , L. Sebastiani , S. Vagnozzi

In this paper we investigate the inflationary dynamics of an $f(R)$ gravity in the presence of a canonical scalar field. We specifically choose the cosmological evolution to be a quasi-de Sitter evolution and also the $f(R)$ gravity is…

General Relativity and Quantum Cosmology · Physics 2018-08-01 K. Kleidis , V. K. Oikonomou
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