Testing Einstein's equivalence principle with short gamma-ray bursts: Table 1.

Sang, Yu; Lin, Hai-Nan; Chang, Zhe

doi:10.1093/mnras/stw1136

Cited by 19 publications

(12 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, it implicitly assumes that the trajectory is short enough that one can treat the region of spacetime containing it as Minkowski plus a linear perturbation, to a good approximation. We will see that this assumption is well justified for sources like GW170817, but not for sources with redshifts z > ∼ 1, like, for instance, the gamma-ray bursts at z = 1.5, z = 2.2, z = 2.6, or even z = 11.97 considered in [14], [23], [19], and [25], respectively. While Nusser [10] gives a formulation of the constraint that is applicable to more distant sources, the previously cited papers use the standard formulation in Eq.…”

Section: Introductionmentioning

confidence: 95%

Shortcomings of Shapiro delay-based tests of the equivalence principle on cosmological scales

Johnson-McDaniel

Sakellariadou

2019

Phys. Rev. D

View full text Add to dashboard Cite

The "Shapiro delay" experienced by an astronomical messenger traveling through a gravitational field has been used to place constraints on possible deviations from the equivalence principle. The standard Shapiro delay used to obtain these constraints is not itself an observable in general relativity, but is rather obtained by comparing with a fiducial Euclidean distance. There is not a mapping between the constraints obtained in this manner and alternative theories that exhibit equivalence principle violations. However, even assuming that the comparison with the fiducial Euclidean distance is carried out in a way that is useful for some class of alternative theories, we show that the standard calculation of these constraints cannot be applied on cosmological scales, as is often done. Specifically, we find that the Shapiro delay computed in the standard way (taking the Newtonian potential to vanish at infinity) diverges as one includes many remote sources. We use an infinite homogeneous lattice model to illustrate this divergence, and also show how the divergence can be cured by using Fermi coordinates associated with an observer. With this correction, one finds that the Shapiro delay is no longer monotonic with the number of sources. Thus, one cannot compute a conservative lower bound on the Shapiro delay using a subset of the sources of the gravitational field without further assumptions and/or observational input. As an illustration, we compute the Shapiro delay by applying the Fermi coordinate expression to two catalogs of galaxy clusters, illustrating the dependence of the result on the completeness of the catalogue and the mass estimates.

show abstract

Section: Introductionmentioning

confidence: 95%

Shortcomings of Shapiro delay-based tests of the equivalence principle on cosmological scales

Johnson-McDaniel

Sakellariadou

2019

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…The majority of previous attempts to constrain violations of the WEP via ∆γ ij with GRBs [18,[51][52][53][54], FRBs [6,[55][56][57][58], Supernovae [59,60], Gravitational Waves [61][62][63][64][65][66][67][68][69], Blazar Flares [70][71][72][73][74] or Pulsars [75][76][77][78] have assumed that the gravitational potential is dominated by the contribution from the Milky Way and/or other massive objects such as the Laniakea supercluster. This has two major shortcomings for distant sources: firstly the gravitational potential in Equation 2 should be a fluctuation about the cosmological mean (and thus can take either sign, unlike in the multiple-source approximation where it is strictly additive), and secondly the long range behaviour of the gravitational potential means that we cannot neglect the large-scale distribution of mass [8,9].…”

Section: B Comparison With the Literaturementioning

confidence: 99%

Constraints on Equivalence Principle Violation from Gamma Ray Bursts

Bartlett,

Bergsdal,

Desmond

et al. 2021

Preprint

View full text Add to dashboard Cite

Theories of gravity that obey the Weak Equivalence Principle have the same Parametrised Post-Newtonian parameter γ for all particles at all energies. The large Shapiro time delays of extragalactic sources allow us to put tight constraints on differences in γ between photons of different frequencies from spectral lag data, since a non-zero ∆γ would result in a frequency-dependent arrival time. The majority of previous constraints have assumed that the Shapiro time delay is dominated by a few local massive objects, although this is a poor approximation for distant sources. In this work we consider the cosmological context of these sources by developing a source-by-source, Monte Carlo-based forward model for the Shapiro time delays by combining constrained realisations of the local density field using the BORG algorithm with unconstrained large-scale modes. Propagating uncertainties in the density field reconstruction and marginalising over an empirical model describing other contributions to the time delay, we use spectral lag data of Gamma Ray Bursts from the BATSE satellite to constrain ∆γ < 3.4 × 10 −15 at 1σ confidence between photon energies of 25 keV and 325 keV.

show abstract

“…photons and neutrinos) or two (same) particles with different energies into account (therefore with different γ 1 and γ 2 ), it is possible to constrain EEP since the theories of gravity that are built in agreement with it predict γ 1 = γ 2 . The accuracy of the EEP has been tested through the difference of the γ values, ∆γ ≡ γ 1 − γ 2 , using several astronomical sources: supernova 1987A [11,12], gammaray bursts (GRBs) [10,[13][14][15][16], fast radio bursts (FRBs) [15,[17][18][19], the Crab pulsar [20][21][22], blazars [23,24] and gravitational wave (GW) sources [25][26][27][28]. Very recently, the association of GW and GRB observations was used to provide a new constraint on the ∆γ through the time delay between the gravitational and electromagnetic radiation produced by a binary neutron star merger [29].…”

Section: Introductionmentioning

confidence: 99%

Cosmic transients, Einstein’s Equivalence Principle and dark matter halos

Bertolami

Landim

2018

Physics of the Dark Universe

View full text Add to dashboard Cite

Cosmic transients, such as gamma-ray bursts and fast radio bursts, have been used to constrain the Einstein's Equivalence Principle (EEP) trough the parametrized-post-Newtonian (PPN) formalism. In this approach, the time delay of photons with different energies from these cosmic transients are used to obtain upper bounds on the difference of the PPN γ parameter. In this work we assume that an important contribution to the time delay is due to the dark matter halo of the Milky Way and consider the dark matter mass distribution given by the Navarro-Frenk-White profile. We obtain the upper limit on the difference of the PPN parameter γ for the polarized gamma-ray emission of GRB 110721A, ∆γ < 1.06 × 10 −28 , the most stringent limit to date on the EEP. In addition, we show that a very similar upper bound is obtained if, instead of having a dark matter component, a visible matter density profile and a non-minimal gravitational coupling between curvature and matter are present.

show abstract

Testing Einstein's equivalence principle with short gamma-ray bursts: Table 1.

Cited by 19 publications

References 41 publications

Shortcomings of Shapiro delay-based tests of the equivalence principle on cosmological scales

Shortcomings of Shapiro delay-based tests of the equivalence principle on cosmological scales

Constraints on Equivalence Principle Violation from Gamma Ray Bursts

Cosmic transients, Einstein’s Equivalence Principle and dark matter halos

Contact Info

Product

Resources

About