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Author Moretti, F.; Bombacigno, F.; Montani, G.
Title The Role of Longitudinal Polarizations in Horndeski and Macroscopic Gravity: Introducing Gravitational Plasmas Type Journal Article
Year 2021 Publication Universe Abbreviated Journal Universe
Volume 7 Issue 12 Pages 496 - 28pp
Keywords gravitational waves; gauge-invariant method; Landau damping; macroscopic gravity
Abstract We discuss some general and relevant features of longitudinal gravitational modes in Horndeski gravity and their interaction with matter media. Adopting a gauge-invariant formulation, we clarify how massive scalar and vector fields can induce additional transverse and longitudinal excitations, resulting in breathing, vector, and longitudinal polarizations. We review, then, the interaction of standard gravitational waves with a molecular medium, outlining the emergence of effective massive gravitons, induced by the net quadrupole moment due to molecule deformation. Finally, we investigate the interaction of the massive mode in Horndeski gravity with a noncollisional medium, showing that Landau damping phenomenon can occur in the gravitational sector as well. That allows us to introduce the concept of “gravitational plasma”, where inertial forces associated with the background field play the role of cold ions in electromagnetic plasma.
Address [Moretti, Fabio; Montani, Giovanni] Sapienza Univ Rome, Dept Phys, Ple Aldo Moro 5, I-00185 Rome, Italy, Email: fabio.moretti@uniroma1.it;
Corporate Author Thesis
Publisher (up) Mdpi Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes WOS:000741918900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5076
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Author Mendoza, S.; Olmo, G.J.
Title Astrophysical constraints and insights on extended relativistic gravity Type Journal Article
Year 2015 Publication Astrophysics and Space Science Abbreviated Journal Astrophys. Space Sci.
Volume 357 Issue 2 Pages 133 - 6pp
Keywords Gravitation; Relativistic processes; Gravitational lensing: weak
Abstract We give precise details to support that observations of gravitational lensing at scales of individual, groups and clusters of galaxies can be understood in terms of nonNewtonian gravitational interactions with a relativistic structure compatible with the Einstein Equivalence Principle. This result is derived on very general grounds without knowing the underlying structure of the gravitational field equations. As such, any developed gravitational theory built to deal with these astrophysical scales needs to reproduce the obtained results of this article.
Address [Mendoza, S.] Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico, Email: sergio@astro.unam.mx;
Corporate Author Thesis
Publisher (up) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-640x ISBN Medium
Area Expedition Conference
Notes WOS:000354392900038 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2234
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Author Aggarwal, N. et al; Figueroa, D.G.
Title Challenges and opportunities of gravitational-wave searches at MHz to GHz frequencies Type Journal Article
Year 2021 Publication Living Reviews in Relativity Abbreviated Journal Living Rev. Relativ.
Volume 24 Issue 1 Pages 4 - 74pp
Keywords Ultra-high-frequency gravitational waves; Cosmological gravitational waves; Gravitational wave detectors; Fundamental physics with gavitational waves
Abstract The first direct measurement of gravitational waves by the LIGO and Virgo collaborations has opened up new avenues to explore our Universe. This white paper outlines the challenges and gains expected in gravitational-wave searches at frequencies above the LIGO/Virgo band, with a particular focus on Ultra High-Frequency Gravitational Waves (UHF-GWs), covering the MHz to GHz range. The absence of known astrophysical sources in this frequency range provides a unique opportunity to discover physics beyond the Standard Model operating both in the early and late Universe, and we highlight some of the most promising gravitational sources. We review several detector concepts that have been proposed to take up this challenge, and compare their expected sensitivity with the signal strength predicted in various models. This report is the summary of the workshop “Challenges and opportunities of high-frequency gravitational wave detection” held at ICTP Trieste, Italy in October 2019, that set up the stage for the recently launched Ultra-High-Frequency Gravitational Wave (UHF-GW) initiative.
Address [Aggarwal, Nancy] Northwestern Univ, Dept Phys & Astron, Ctr Interdisciplinary Explorat & Res Astrophys CI, Ctr Fundamental Phys, Evanston, IL 60208 USA, Email: nancy.aggarwal@northwestern.edu;
Corporate Author Thesis
Publisher (up) Springer Int Publ Ag Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2367-3613 ISBN Medium
Area Expedition Conference
Notes WOS:000727359500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5074
Permanent link to this record