相关论文: Spontaneous Scalarization with Massive Fields
We present the first fully non-linear evolutions of binary neutron star mergers in a moving-punctures approach in Einstein-scalar-Gauss-Bonnet gravity. We study both linear and quadratic-type couplings between the scalar and the…
Compact stars in scalar-tensor (ST) gravity have been extensively investigated, but relatively few studies have focused on highly relativistic neutron stars (NSs) with an extremely dense core region where the trace of the energy-momentum…
We perform multi-dimensional core-collapse supernova (CCSN) simulations in a massive scalar-tensor theory for the first time with a realistic equation of state and multi-energy neutrino radiation. Among the set of our models varying the…
We describe scalar-bimetric theories where the dynamics of the Universe are governed by two separate metrics, each with an Einstein-Hilbert term. In this setting, the baryonic and dark matter components of the Universe couple to metrics…
Many classes of extended scalar-tensor theories predict that dynamical instabilities can take place at high energies, leading to the formation of scalarized neutron stars. Depending on the theory parameters, stars in a scalarized state can…
Modified gravity models which include an additional propagating degree of freedom are typically studied in the quasi-static limit, where the propagation is neglected, and the wave equation of the field is replaced with a Poisson-type…
We present the field equations governing the equilibrium of rapidly rotating neutron stars in scalar-tensor theories of gravity, as well as representative numerical solutions. The conditions for the presence of a nontrivial scalar field and…
Tensor-scalar theory of gravity allows the generation of gravitational waves from astrophysical sources, like Supernov\ae{}, even in the spherical case. That motivated us to study the collapse of a degenerate stellar core, within…
We study the spontaneous scalarization of a standard conducting charged sphere embedded in Maxwell-scalar models in flat spacetime, wherein the scalar field $\phi$ is nonminimally coupled to the Maxwell electrodynamics. This setup serves as…
For massless scalar fields, a relation $\Delta_{n}=\frac{\sqrt{3}}{2}\pi$ for $n\rightarrow \infty$ was observed in the scalar-Gauss-Bonnet theory. In the present paper, we extend the discussion by including a nonzero scalar field mass. For…
It is investigated if massless particles can couple to scalar fields in a special relativistic theory with classical particles. The only possible obvious theory which is invariant under Lorentz transformations and reparametrization of the…
In the present work we study the scalar singlet as well as the Two-Higgs Doublet model inert dark matter particles impact on compact objects, and we provide the first constraints of the parameter space using neutron stars. The models…
The paper studied the scalar and gauge fields on the background metric of Kasner in the multidimensional spacetime. Influence of metric effects leads to renormalization of main parameters of the fields in the Lagrangian, and new mass and…
Scalar-tensor theories with a scalar field coupled to the Gauss-Bonnet invariant can evade no-hair theorems and allow for non-trivial scalar profiles around black holes. This coupling is characterized by a length scale $\lambda$, which, in…
Spontaneous scalarization is a gravitational phenomenon in which deviations from general relativity arise once a certain threshold in curvature is exceeded, while being entirely absent below that threshold. For black holes, scalarization is…
We study the parameterized post-Newtonian approximation in teleparallel model of gravity with a scalar field. The scalar field is non-minimally coupled to the scalar torsion as well as to the boundary term introduced in [1]. We show that,…
We propose a new model of black hole spontaneous scalarization that combines a scalar--Gauss--Bonnet interaction with a non--minimal coupling to a U(1) gauge field (a dark photon or an electromagnetic field). This construction generalizes…
In this paper we study brane-world scenarios with a bulk scalar field, using a covariant formalism to obtain a 4D Einstein equation via projection onto the brane. We discuss, in detail, the effects of the bulk on the brane and how the…
We examine the effects of a scalar field, coupled only to neutrinos, on oscillations among weak interaction current eigenstates. The existence of a real scalar field is manifested as effective masses for the neutrino mass eigenstates, the…
Scalar-tensor theories (STTs) are a widely studied alternative to General Relativity (GR) in which gravity is endowed with an additional scalar degree of freedom. Although severely constrained by solar system and pulsar timing experiments,…