We analyze the propagation of gravitational waves in metric f(R) theories of gravity, on the special setting of flat background geometry (Minkowski spacetime). In particular, adopting a gauge invariant formalism, we clearly establish that the exact number of propagating degrees of freedom is three, consisting of the standard tensorial modes along with an additional massive scalar field. Then, investigating their effects on test masses via the geodesic deviation equation, we show that the additional dynamical degree contained in such extended formulations is actually detectable as a superposition of longitudinal and breathing stresses, which even though in principle correspond to distinct pure polarizations turn out to be never separable in the wave dynamics and cannot be interpreted as a proper independent excitations.

Gauge invariant formulation of metric f (R) gravity for gravitational waves / Moretti, F.; Bombacigno, F.; Montani, G.. - In: PHYSICAL REVIEW D. - ISSN 2470-0010. - 100:8(2019). [10.1103/PhysRevD.100.084014]

Gauge invariant formulation of metric f (R) gravity for gravitational waves

Moretti F.
;
Bombacigno F.;Montani G.
2019

Abstract

We analyze the propagation of gravitational waves in metric f(R) theories of gravity, on the special setting of flat background geometry (Minkowski spacetime). In particular, adopting a gauge invariant formalism, we clearly establish that the exact number of propagating degrees of freedom is three, consisting of the standard tensorial modes along with an additional massive scalar field. Then, investigating their effects on test masses via the geodesic deviation equation, we show that the additional dynamical degree contained in such extended formulations is actually detectable as a superposition of longitudinal and breathing stresses, which even though in principle correspond to distinct pure polarizations turn out to be never separable in the wave dynamics and cannot be interpreted as a proper independent excitations.
2019
f(R) gravity; gravitational waves; polarizations; scalar polarization; breathing; longitudinal; modified gravity
01 Pubblicazione su rivista::01a Articolo in rivista
Gauge invariant formulation of metric f (R) gravity for gravitational waves / Moretti, F.; Bombacigno, F.; Montani, G.. - In: PHYSICAL REVIEW D. - ISSN 2470-0010. - 100:8(2019). [10.1103/PhysRevD.100.084014]
File allegati a questo prodotto
File Dimensione Formato  
Moretti_Gauge_2019.pdf

accesso aperto

Tipologia: Documento in Post-print (versione successiva alla peer review e accettata per la pubblicazione)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 177.58 kB
Formato Adobe PDF
177.58 kB Adobe PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1347142
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 21
  • ???jsp.display-item.citation.isi??? 20
social impact