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Related papers: Cosmological Frequency Combs

200 papers

Features in the inflationary landscape can inject extra energies to inflation models and produce on-shell particles with masses much larger than the Hubble scale of inflation. This possibility extends the energy reach of the program of…

High Energy Physics - Phenomenology · Physics 2022-09-02 Xingang Chen , Reza Ebadi , Soubhik Kumar

To find more deliberate f(R,T) cosmological solutions, we proceed our previous paper further by studying some new aspects of the considered models via investigation of some new cosmological parameters/quantities to attain the most…

General Relativity and Quantum Cosmology · Physics 2017-05-23 Hamid Shabani , Mehrdad Farhoudi

Frequency-modulated (FM) combs feature flat intensity spectra with a linear frequency chirp, useful for metrology and sensing applications. Generating FM combs in semiconductor lasers generally requires a fast saturable gain, usually…

The current cosmic time evolution of the Universe is described by the General Relativity theory when a cosmological principle is considered under a flat space time landscape. The set of known as Friedmann equations, contain the principles…

General Relativity and Quantum Cosmology · Physics 2022-06-20 Rodrigo Sandoval-Orozco , Celia Escamilla-Rivera

We consider the evolution of a flat Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, in the presence of variable gravitational and cosmological constants. The basic equation for the Hubble…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. K. Mak , J. A. Belinchon , T. Harko

We discuss the asymmetry of cosmic background evolution in time with respect to the quantum bounce in the Loop Quantum Cosmology (LQC), employing the value of scalar field at the bounce $\phi_{\rm B}$. We use the Chaotic and the $R^2$…

General Relativity and Quantum Cosmology · Physics 2019-07-03 Wen-Hsuan Lucky Chang , Jiun-Huei Proty Wu

Cosmological correlators capture the spatial fluctuations imprinted during the earliest episodes of the universe. While they are generally very non-trivial functions of the kinematic variables, they are known to arise as solutions to…

High Energy Physics - Theory · Physics 2024-04-08 Thomas W. Grimm , Arno Hoefnagels , Mick van Vliet

A dynamical scalar field represents the simplest generalization of a pure Cosmological Constant as a candidate to explain the recent evidence in favour of the accelerated cosmic expansion. We review the dynamical properties of such a…

Astrophysics · Physics 2011-07-19 C. Baccigalupi , A. Balbi , S. Matarrese , F. Perrotta , N. Vittorio

Local measurements of the Hubble parameter are increasingly in tension with the value inferred from a $\Lambda$CDM fit to the cosmic microwave background (CMB) data. In this paper, we construct scenarios in which evolving scalar fields…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-13 Prateek Agrawal , Francis-Yan Cyr-Racine , David Pinner , Lisa Randall

We consider scalar perturbations of energy--density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine--tuning for graceful exit, towards the standard Friedman eras of observed…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Capozziello , G. Lambiase , G. Scarpetta

Spatially averaged inhomogeneous cosmologies in classical general relativity can be written in the form of effective Friedmann equations with sources that include backreaction terms. In this paper we propose to describe these backreaction…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Thomas Buchert , Julien Larena , Jean-Michel Alimi

In this paper we study dynamics of the closed FRW model with holonomy corrections coming from loop quantum cosmology. We consider models with a scalar field and cosmological constant. In case of the models with cosmological constant and…

General Relativity and Quantum Cosmology · Physics 2009-11-19 Jakub Mielczarek , Orest Hrycyna , Marek Szydlowski

High finesse frequency combs (HFC) with large ratio of the frequency spacing to the width of the spectral components have demonstrated remarkable results in many applications such as precision spectroscopy and metrology. We found that low…

In the present work we perform a phase-plane analysis of the complete dynamical system corresponding to a flat FRW cosmological models with a perfect fluid and a self-interacting scalar field and show that every positive and monotonous…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Ana Nunes , Jose P. Mimoso

Frequency modulated (FM) frequency combs constitute an exciting alternative to generate equidistant spectra. The full set of Maxwell-Bloch equations is reduced to a single master equation for FM combs with fast dynamics to provide insight…

Optics · Physics 2019-12-18 Nikola Opačak , Benedikt Schwarz

We construct new classes of cosmological solutions in modified and Einstein gravity theories encoding space-time quasicrystal, STQC, configurations modelled by nonlinear self-organized and pattern forming quasi-periodic structures. Such…

General Physics · Physics 2018-12-04 Sergiu I. Vacaru

The last decades have witnessed an unprecedented advancement in our knowledge of the large scale universe. In particular, increasingly accurate cosmological observations have allowed us to discover a form of "dark energy", which presently…

General Relativity and Quantum Cosmology · Physics 2022-04-11 Eduardo Amancio Barbosa Oliveira

We consider Friedmann-Lema\^{\i}tre-Robertson-Walker flat cosmological models in the framework of general Jordan frame scalar-tensor theories of gravity with arbitrary coupling function and potential. For the era when the cosmological…

General Relativity and Quantum Cosmology · Physics 2011-01-06 Laur Järv , Piret Kuusk , Margus Saal

A new approach to tackle Einstein equations for an isotropic and homogeneous Friedmann--Robertson--Walker Universe in the presence of a quintessence scalar field is devised. It provides a way to get a simple exact solution to these…

General Relativity and Quantum Cosmology · Physics 2016-04-12 Felipe A. Asenjo , Sergio A. Hojman