GW170817 constraints on the properties of a neutron star in the presence of WIMP dark matter

Abstract

The properties of a neutron star are studied in the presence of dark matter. We have considered a relatively light weakly interacting massive particle (WIMP) as a dark matter candidate with properties suggested by the results of the DAMA/LIBRA collaboration, realized for instance within the framework of the Next-to-Minimal Supersymmetric Standard Model. The dark matter particle interacts with the baryonic matter of a neutron star through Higgs bosons. The dark matter variables are essentially fixed using the results of the DAMA/LIBRA experiment, which are then used to build the Lagrangian density for the WIMP–nucleon interaction inside a neutron star. We have used the effective field theory motivated relativistic mean field model to study the equations-of-state in the presence of dark matter. The predicted equations-of-state are used in the Tolman–Oppenheimer–Volkoff equations to obtain the mass–radius relations, the moment of inertia, and effects of the tidal field on a neutron star. The calculated properties are compared with the corresponding data of the GW170817 event.

Neutron-star tidal deformability and equation-of-state constraints

“…7), astronomical observations can also be used to place constraints on the relevant parameter space. In general, since GW170817 provided an upper limit onΛ, any physical effect that results in a softening of the equation of state can be consistent with the data [88,[240][241][242][243][244][245][246] As such, a strong first-order phase transition might make an equation of state model compatible with the GW170817 data, even if the hadronic part on its own is not [152,[247][248][249][250]. A number of studies have constructed models that can successfully interpret the inspiral signal from GW170817 as the coalescence of any combination of hadronic and hybrid hadronic-quark neutron stars and place corresponding constraints on the relevant model parameter space [149,247,248,[251][252][253][254][255][256][257][258][259][260].…”

“…If the tidal deformability of black holes is indeed vanishing (or if it is very small), studying tidal effects in mergers of black holes could put constraints on horizon-level spacetime corrections [81]. The tidal deformability can therefore also be used to test the nature of the coalescing compact objects [82][83][84][85][86], or other physics such as dark matter and extra dimensions [87][88][89][90].…”

Interpreting binary neutron star mergers: describing the binary neutron star dynamics, modelling gravitational waveforms, and analyzing detections

“…A NS has a rich spectrum of modes. Those with sufficiently low frequencies could be tidally excited during an inspiral and yield spectroscopic information about matter in NS interiors; several examples have been studied to date [27,216,270,300,317,437,448,493,528,529,561]. Effects from nonlinear mode coupling have also been studied [200,323,550].…”

Leading nonlinear tidal effects and scattering amplitudes

“…In this paper we investigate the effects of tidal deformations [93][94][95] on the conservative two-body Hamiltonian during the inspiral phase, focusing on their structure in the post-Minkowskian expansion. The tidal deformations offer a window into the equation of state of neutrons stars [96][97][98][99] and test our understanding of black holes [83,[100][101][102][103][104][105][106][107] and of possible exotic physics [108][109][110][111][112][113][114]. While tidal effects are expected to vanish for black holes in general relativity [97,[115][116][117][118], they are of crucial importance for understanding the equation of state of neutron stars.…”