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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

An important unsolved problem that affects practically all attempts to connect string theory to cosmology and phenomenology is how to distinguish effective field theories belonging to the string landscape from those that are not consistent…

High Energy Physics - Theory · Physics 2019-02-20 Ana Achúcarro , Gonzalo A. Palma

The string theory swampland proposes that there is no UV-completion for an effective field theory with an exact (metastable) de Sitter vacua, thereby ruling out standard $\Lambda$CDM cosmology if the conjecture is taken seriously. The…

High Energy Physics - Theory · Physics 2019-06-20 Suddhasattwa Brahma , Md. Wali Hossain

We use observational data on the large scale structure (LSS) of the Universe measured over a wide range of scales from sub-galactic up to horizon scale and on the cosmic microwave background anisotropies to determine cosmological parameters…

Astrophysics · Physics 2011-07-19 R. Durrer , B. Novosyadlyj

It has recently been argued that string theory does not admit de Sitter vacua. This would imply that the current accelerated expansion of the universe is not driven by a cosmological constant (or vacuum energy) but by other means such as a…

High Energy Physics - Theory · Physics 2019-07-24 Carsten van de Bruck , Cameron C. Thomas

The persistent challenge of creating stable de Sitter vacua within string theory undermines the observational validity of the $\Lambda$ cold dark matter (CDM) model. This difficulty suggests that the concordance model of cosmology,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Luis A. Anchordoqui , Dieter Lust

The main aim of this paper is to present the multi scalar field components as candidates to be the dark energy of the universe and their observational constraints. We start with the canonical Quintessence and Phantom fields with quadratic…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-12 J. Alberto Vázquez , David Tamayo , Gabriela Garcia-Arroyo , Isidro Gómez-Vargas , Israel Quiros , Anjan A. Sen

Implications of the string Swampland criteria for a dark energy dominated universe, obtained by using Gaussian processes and $H(z)$ data analysis, are discussed. In particular, the Swampland criteria for a scalar-field dark energy, without…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-05 Emilio Elizalde , Martiros Khurshudyan

We investigate the constraints on cosmological parameters especially for EoS of dark energy, inflationary parameters, neutrino mass and curvature of universe using simulated Planck data. Firstly we determine cosmological parameters with…

Astrophysics · Physics 2014-11-18 Jun-Qing Xia , Hong Li , Gong-Bo Zhao , Xinmin Zhang

We study the minimally and non-minimally coupled scalar field models as possible alternatives for dark energy, the mysterious energy component that is driving the accelerated expansion of the universe. After discussing the dynamics at both…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Zahra Davari , Valerio Marra , Mohammad Malekjani

The main aim of this paper is to provide cosmological constraints on the Multi Scalar Field Dark Matter model (MSFDM), in which we assume the dark matter is made up of different ultra-light scalar fields. As a first approximation, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-05 L. O. Téllez-Tovar , Tonatiuh Matos , J. Alberto Vázquez

If the dark energy is modelled as a relativistic elastic solid then the standard CDM and $\Lambda$CDM models, as well as lattice configurations of cosmic strings or domain walls, are points in the two-dimensional parameter space $(w,c_{\rm…

Astrophysics · Physics 2010-12-09 Richard A. Battye , Adam Moss

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

By combining swampland conjectures with observational data, it was recently suggested that the cosmological hierarchy problem (i.e. the smallness of the dark energy in Planck units) could be understood as an asymptotic limit in field space,…

High Energy Physics - Theory · Physics 2024-05-14 Luis Anchordoqui , Ignatios Antoniadis , Dieter Lust

The $\Lambda$CDM cosmological model provides to first approximation a good description of the universe, but various tensions with data, most notably Hubble tension, persist. In this work we confront $\Lambda$CDM with the Pantheon Type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-11 Eoin Ó Colgáin

The observational data on the large scale structure (LSS) of the Universe are used to determine cosmological parameters within the class of adiabatic inflationary models. We show that a mixed dark matter model with cosmological constant…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , R. Durrer , S. Apunevych

Motivated by astrophysical observations of excess electronic production in the galaxy, new theoretical models of the dark matter sector have been proposed in which the Standard model couples to the dark matter sector through an attractive…

High Energy Physics - Theory · Physics 2009-08-07 Betti Hartmann , Farhad Arbabzadah

We present a general model-independent approach to study the coupled dark energy and the string Swampland criteria. We show how the dark sector interaction is degenerated with the equation of state of dark energy in the context of the…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Tao Yang

The dynamics of expansion and large scale structure formation of the Universe are analyzed for models with dark energy in the form of a phantom scalar field which initially mimics a $\Lambda$-term and evolves slowly to the Big Rip…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Bohdan Novosyadlyj , Olga Sergijenko , Ruth Durrer , Volodymyr Pelykh

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
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