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Related papers: Swampland criteria for rescaled Einstein-Hilbert g…

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We provide a refined and much more simplified Einstein-Gauss-Bonnet inflationary theoretical framework, which is compatible with the GW170817 observational constraints on the gravitational wave speed. As in previous works, the constraint…

General Relativity and Quantum Cosmology · Physics 2021-09-22 V. K. Oikonomou

Assuming that a scalar field controls the inflationary era, we examine the combined effects of string and $f(R)$ gravity corrections on the inflationary dynamics of canonical scalar field inflation, imposing the constraint that the speed of…

General Relativity and Quantum Cosmology · Physics 2020-12-30 S. D. Odintsov , V. K. Oikonomou , F. P. Fronimos

Power-law corrections (having the exponent strictly between 2 and 3) to the Einstein-Hilbert action yield an extended theory of gravity which is consistent with Solar-System tests and properly reproduces the main phases of the Universe…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-13 Salvatore Capozziello , Nakia Carlevaro , Mariafelicia De Laurentis , Massimiliano Lattanzi , Giovanni Montani

We study constraints imposed by two proposed string Swampland criteria on cosmology. These criteria involve an upper bound on the range traversed by scalar fields as well as a lower bound on $|\nabla_{\phi} V|/V$ when $V >0$. We find that…

High Energy Physics - Theory · Physics 2018-10-17 Prateek Agrawal , Georges Obied , Paul J. Steinhardt , Cumrun Vafa

We consider the implications of the swampland conjectures on scalar-tensor theories defined in the Einstein frame in which the scalar interaction is screened. We show that chameleon models are not in the swampland provided the coupling to…

High Energy Physics - Theory · Physics 2020-04-15 Philippe Brax , Carsten van de Bruck , Anne-Christine Davis

One class of single-field inflationary models compatible with the recently-conjectured Swampland criteria would be those in which a Hubble slow-roll parameter $\epsilon_\text{H}$ is not the same as $\epsilon_\text{V} \sim (V'/V)^2$.…

High Energy Physics - Theory · Physics 2019-03-06 Suddhasattwa Brahma , Md. Wali Hossain

Recently researchers have been studying various conditions as swampland criteria in cosmological implications. They have studied many inflation models with different swampland conditions. Occasionally these conjectures are modified and lead…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-14 S. Noori Gashti , J. Sadeghi , B. Pourhassan

We investigate an ability of the exponential power-law inflation to be phenomenologically correct model of the early universe. GR scalar cosmology equations we study in Ivanov-Salopek-Bond (or Hamilton-Jacobi like) representation where the…

General Relativity and Quantum Cosmology · Physics 2025-01-22 I. V. Fomin , S. V. Chervon

The recently proposed Swampland Criteria aim to evade any (meta-)stable de Sitter constructions within String landscapes, making it difficult to accommodate accelerating phases, like dark energy domination and inflationary epoch, in…

High Energy Physics - Theory · Physics 2019-04-12 Suratna Das

In this Letter, we study the implications of string Swampland criteria for dark energy in view of ongoing and future cosmological observations. If string theory should be the ultimate quantum gravity theory, there is evidence that exact de…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Lavinia Heisenberg , Matthias Bartelmann , Robert Brandenberger , Alexandre Refregier

The string $\alpha^\prime$-correction to the usual Einstein action comprises a Gauss-Bonnet integrand multiplied by non-trivial functions of the modulus field $\chi$ and/or the dilaton field $\phi$. We discuss how the presence of such terms…

High Energy Physics - Theory · Physics 2007-05-23 Ishwaree P Neupane

We consider power-law inflation with a Gauss-Bonnet correction inspired by string theory. We analyze the stability of cosmological perturbations and obtain the allowed parameter space. We find that for GB-dominated inflation ultra-violet…

High Energy Physics - Theory · Physics 2009-09-18 Zong-Kuan Guo , Dominik J. Schwarz

The scenario of the slow-roll inflation is studied in the frame of the scalar-tensor theory of gravity where the scalar field has a non-minimal coupling to the geometric part. After deriving the main dynamical and perturbation equations,…

General Relativity and Quantum Cosmology · Physics 2020-12-01 Abolhassan Mohammadi , Tayeb Golanbari , Jamil Enayati , Shahram Jalalzadeh , Khaled Saaidi

Phantom divide line transitions are not possible in the context of single scalar field scalar-tensor theories. In this article we study a combined framework of a tachyonic minimally coupled single scalar field theory in the presence of an…

General Relativity and Quantum Cosmology · Physics 2026-03-11 S. D. Odintsov , V. K. Oikonomou

In this work we shall study Einstein Gauss-Bonnet theories and we investigate when these can have their gravitational wave speed equal to the speed of light, which is unity in natural units, thus becoming compatible with the striking event…

General Relativity and Quantum Cosmology · Physics 2019-10-02 S. D. Odintsov , V. K. Oikonomou

We investigate the extent to which the Swampland Conjecture can be employed to constrain large-field inflationary models from the perspective of quantum gravity consistency. In particular, we focus on the Swampland Distance Conjecture,…

High Energy Physics - Theory · Physics 2025-11-07 Yuma S. Furuta , Yuta Hamada , Kazunori Kohri

The First and Second Swampland Conjectures (FSC & SSC) are substantially modified in non-critical string cosmology, in which cosmic time is identified with the time-like Liouville mode of the supercritical string. In this scenario the…

High Energy Physics - Theory · Physics 2020-09-02 John Ellis , Nick Mavromatos , Dimitri Nanopoulos

We discuss the viability of $f(R)$ and Brans-Dicke theories of gravity in light of the recent Swampland conjectures. We show that in the case of perfect fluid domination the swampland conjecture conditions may be easily satisfied and…

General Relativity and Quantum Cosmology · Physics 2019-06-05 Michal Artymowski , Ido Ben-Dayan

Inflationary era of our Universe can be characterized as semi-classical because it can be described in the context of four-dimensional Einsteins's gravity involving quantum corrections. These string motivated corrections originate from…

General Relativity and Quantum Cosmology · Physics 2021-08-25 S. A. Venikoudis , F. P. Fronimos

We investigate the consistency of radiatively corrected inflationary models with both the latest observational data from the Atacama Cosmology Telescope (ACT) combined with Planck 2018 and Baryon Acoustic Oscillation (BAO) measurements, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-27 Mohammad Ali S Afshar , Saeed Noori Gashti , Mohammad Reza Alipour , Behnam Pourhassan , Izzet Sakalli , Jafar Sadeghi