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Spectrum of Primordial Gravitational Waves in Modified Gravities: A Short Overview [article]

S.D. Odintsov, V.K. Oikonomou, R. Myrzakulov
2022 arXiv   pre-print
In this work we shall exhaustively study the effects of modified gravity on the energy spectrum of the primordial gravitational waves background. S.  ...  With this sort review, our main aim is to gather all the necessary information for studying the effects of modified gravity on primordial gravitational waves in a concrete and quantitative way and in a  ...  ACKNOWLEDGMENTS This paper was supported by the Ministry of Education and Science of Kazakhstan, Grant AP09261147.  ... 
arXiv:2204.00876v1 fatcat:cn2aheqbbjbblkawljjsik3o44

Spectrum of Primordial Gravitational Waves in Modified Gravities: A Short Overview

Sergei D. Odintsov, Vasilis K. Oikonomou, Ratbay Myrzakulov
2022 Symmetry  
With this short review, our main aim is to gather all the necessary information for studying the effects of modified gravity on primordial gravitational waves in a concrete and quantitative way and in  ...  In this work, we shall exhaustively study the effects of modified gravity on the energy spectrum of the primordial gravitational waves background. S.  ...  Conflicts of Interest: The authors declare no conflicts of interest.  ... 
doi:10.3390/sym14040729 fatcat:xeq5jkax5rfgvklkas4dcykgym

Brane-World Gravity

Roy Maartens, Kazuya Koyama
2010 Living Reviews in Relativity  
We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies -- the 5-dimensional Dvali--Gabadadze--Porrati models.  ...  This revolutionary picture arises in the framework of recent developments in M theory.  ...  The spectrum of the stochastic gravitational waves is modified to Ω ref = {︃ 6 −2 3 +1 for < crit , 6 +2 3 +2 for > crit , (385) where is an equation of state.  ... 
doi:10.12942/lrr-2010-5 pmid:28690420 pmcid:PMC5479361 fatcat:ysr2pwlpu5frpap3xex7rfiznq

Phenomenology of theories of gravity without Lorentz invariance: The preferred frame case

Diego Blas, Eugene Lim
2014 International Journal of Modern Physics D  
Theories of gravitation without Lorentz invariance are candidates of low-energy descriptions of quantum gravity.  ...  In this review we will describe the phenomenological consequences of the candidates associated to the existence of a preferred time direction  ...  Yunes for clarifications about the effects of LV in the strong gravity regime. EAL is supported by STFC AGP grant ST/L000717/1.  ... 
doi:10.1142/s0218271814430093 fatcat:gdgfcw3blfd5bilhly4yt3c6ca

Analogue Gravity

Carlos Barceló, Stefano Liberati, Matt Visser
2011 Living Reviews in Relativity  
The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article.  ...  Analogue gravity is a research programme which investigates analogues of general relativistic gravitational fields within other physical systems, typically but not exclusively condensed matter systems,  ...  We expect that these analogue models provide us with new insights as to how their inherent modified-dispersion relations affect cosmological processes such as the generation of a primordial spectrum of  ... 
doi:10.12942/lrr-2011-3 pmid:28179830 pmcid:PMC5255896 fatcat:7wjwg3x46jbufazbldfkzswdai

CMB anisotropies induced by tensor modes in Massive Gravity

Dennis Bessada, Oswaldo D Miranda
2009 Journal of Cosmology and Astroparticle Physics  
We study Gravitational Waves (GWs) in the context of Massive Gravity, an extension to General Relativity (GR) where the fluctuations of the metric have a nonzero mass, and specifically investigate the  ...  We first study the time evolution of the tensor modes in Massive Gravity and show that there is a graviton mass limit m_l=10^-66g∼ 10^-29cm^-1, so that for masses m≤ m_l the tensor perturbations in Massive  ...  DB thanks Cesar A. Costa and Cláudio Brandão for a great help on numerical methods. DB was financially supported by CAPES, and ODM is partially supported by CNPq (grant 305456/2006-7).  ... 
doi:10.1088/1475-7516/2009/08/033 fatcat:k3htpf5xcjbbjfbtcmpeqe3csy

Tracing the high energy theory of gravity: an introduction to Palatini inflation [article]

Tommi Tenkanen
2020 arXiv   pre-print
We also discuss some prospects for future research and argue why r=10^-3 is a particularly important goal for future missions that search for signatures of primordial gravitational waves.  ...  In scenarios where the field(s) responsible for cosmic inflation are coupled non-minimally to gravity or the gravitational sector is otherwise extended, assumptions of the underlying gravitational degrees  ...  discuss a particularly important goal for future missions that search for signatures of primordial gravitational waves.  ... 
arXiv:2001.10135v1 fatcat:wcqz5bvapndg7lzy7gldgltrou

Cosmological tests of gravity

Bhuvnesh Jain, Justin Khoury
2010 Annals of Physics  
We describe general features of the modified Friedman equation in such theories. The second half of this review describes experimental tests of gravity in light of the new theoretical approaches.  ...  We review recent developments in modified gravity theories, focusing on higher dimensional approaches and chameleon/f(R) theories.  ...  Future gravitational wave experiments such as LISA can detect gravitational waves from distant supermassive black hole pairs in the coalescence phase [162] ; however these tests as well as a variety of  ... 
doi:10.1016/j.aop.2010.04.002 fatcat:hcqhynvndvgpvjbispfzuwlbfu

Testing Screened Modified Gravity

Philippe Brax, Santiago Casas, Harry Desmond, Benjamin Elder
2021 Universe  
In this short review, we shall present the various screening mechanisms from an effective field theory point of view.  ...  Long range scalar fields with a coupling to matter appear to violate known bounds on gravitation in the solar system and the laboratory. This is evaded thanks to screening mechanisms.  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/universe8010011 fatcat:ek7vwn57sfathh6ijv36mhrm4a

MATTERS OF GRAVITY, a newsletter for the gravity community, Number 3 [article]

Jorge Pullin
1994 arXiv   pre-print
Table of contents Editorial Correspondents Gravity News: Open Letter to gravitational physicists, Beverly Berger A Missouri relativist in King Gustav's Court, Clifford Will Gary Horowitz wins the Xanthopoulos  ...  , Richard Hammond Conference reports: Gravitational waves from coalescing compact binaries, Curt Cutler Mach's principle: from Newton's bucket to quantum gravity, Dieter Brill Cornelius Lanczos international  ...  Robert Caldwell discussed a stochastic background of gravity waves from inflation and the possibility of observing these gravity waves using the cosmic microwave anisotropy.  ... 
arXiv:gr-qc/9402002v1 fatcat:uedi4mapereu7hcttgqlavzqvy

Matters of Gravity, the newsletter of the APS Topical Group on Gravitation, Fall 2003 [article]

Jorge Pullin
2003 arXiv   pre-print
coast gravity meeting, by Charles Torre - Astrophysics of gravitational wave sources, by Joan Centrella - Gravitational interaction of compact objects, by M.  ...  Lehner - PriceFest, by John Whelan - Gravitation: a decennial perspective, by Jorge Pullin  ...  The three LIGO detectors were operating with a noise level about a factor of 100 above the design level, so the probability of detecting any gravitational waves, particularly in such a short run were extremely  ... 
arXiv:gr-qc/0309065v1 fatcat:ht2baxa2bbdj5fyebkw6va2t5e

Pushing gravity: new perspectives on Le Sage gravity [article]

Victor Christianto, Matthew R. Edwards
2020 Figshare  
To many readers of physics, the history of theories of gravitation may be summed up approximately as follows.  ...  After a chaotic period featuring vortex ether models and the like, gravity was at last put on a firm scientific footing by Newton.  ...  In consequence, statistics from the entire globe were assembled by men who doubted the possibility of a lunar effect, to prove their case.  ... 
doi:10.6084/m9.figshare.12387275.v1 fatcat:2s447ekqybambi2fib5cnamlfi

Quantum gravity: general introduction and recent developments

C. Kiefer
2006 Annalen der Physik  
I then address quantum gravitational aspects of string theory. This is followed by a discussion of black holes and quantum cosmology.  ...  After giving some general motivations for the need of such a theory, I discuss the main approaches in quantizing general relativity: Covariant approaches (perturbation theory, effective theory, and path  ...  Acknowledgements I thank Christian Heinicke for a critical reading of this article, and Julian Barbour, Hai Lin, and Oliver Winkler for their comments.  ... 
doi:10.1002/andp.200510175 fatcat:33educi4i5gk7mkwaiu4dgx3gq

Quantum fields in curved spacetime, semiclassical gravity, quantum gravity phenomenology, and analogue models: parallel session D4

Christopher J. Fewster, Stefano Liberati
2014 General Relativity and Gravitation  
The talks given in parallel session D4 at the 20th International Conference on General Relativity and Gravitation (Warsaw 2013) are summarized.  ...  The talk by Krämer [32, 8] discussed a derivation of the primordial power spectrum of density fluctuations within such a framework of quantum cosmology.  ...  These consisted in the exploitation of the sub-millikelvin cooling of the normal modes of the ton-scale gravitational wave detector which allowed to place a new strong upper limit for possible Planck-scale  ... 
doi:10.1007/s10714-014-1707-1 fatcat:5gy6z52fp5bufjw2lrmnsmt54q

Asymptotically safe gravity [article]

Astrid Eichhorn
2020 arXiv   pre-print
A concise overview of key results on asymptotically safe gravity is followed by a short discussion of important open questions.  ...  This is an introduction to asymptotically safe quantum gravity, explaining the main idea of asymptotic safety and how it could solve the problem of predictivity in quantum gravity.  ...  One expects quantum gravity to have been important in the early universe, such that observable imprints might have been left in the spectrum of primordial tensor modes.  ... 
arXiv:2003.00044v1 fatcat:n3jqnxi3x5gz7mdtkzuw4gebwe
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