Related papers: Scalar Non-Luminous Matter in Galaxies
An analogue of the Oppenheimer-Synder collapsing model is treated analytically, where the matter source is a scalar field with an exponential potential. An exact solution is derived followed by matching to a suitable exterior geometry, and…
We study flat directions and soft scalar masses using a $Z_3$ orbifold model with $SU(3) \times SU(2) \times U(1)$ gauge group and extra gauge symmetries including an anomalous $U(1)$ symmetry. Soft scalar masses contain $D$-term…
The idea is considered that a classical non-Abelian gauge field can be considered as a dark matter candidate. It is shown that Yang-Mills equations have solutions with such distribution of the mass density that allows to describe a…
In the Minimal Supersymmetric Standard Model (MSSM), the scalar neutrino $\tilde{\nu}_L$ has odd R parity, yet it has long been eliminated as a dark-matter candidate because it scatters elastically off nuclei through the $Z$ boson, yielding…
In this letter, we develop a Newtonian approach to the collapse of galaxy fluctuations of scalar field dark matter under initial conditions inferred from simple assumptions. The full relativistic system, the so called Einstein-Klein-Gordon,…
Scalar-tensor gravity is the simplest and best understood modification of general relativity, consisting of a real scalar field coupled directly to the Ricci scalar curvature. Models of this type have self-accelerating solutions. In an…
Long-lived pseudo-solitonic objects, known as oscillons/oscillatons, which we collectively call real scalar stars, are ubiquitous in early Universe cosmology of scalar field theories. Typical examples are axions stars and moduli stars.…
According to a scalar theory of gravity with a preferred frame, electromagnetism in the presence of a gravitational field implies that there is an additional energy tensor, which might contribute to dark matter. The expression of this…
In this paper, we introduce a non-minimally conformally coupled scalar field and dark matter in F(T) cosmology and study their dynamics. We investigate the stability and phase space behavior of the parameters of the scalar field by choosing…
Scalar fields coupled to three-dimensional gravity are considered. We uncover a scaling symmetry present in the black hole reduced action, and use it to prove a Smarr formula valid for any potential. We also prove that non-rotating hairy…
We study a scalar field in curved space in three dimensions. We obtain a static perturbative solution and show that this solution satisfies the exact equations in the asymptotic region at infinity. The new solution gives rise to a…
We consider a $U(1)_X$ extension of the Standard Model~(SM), where the spontaneous breaking of $U(1)_X$ gauge group results in a pseudo scalar particle which is the proposed candidate for dark matter. In the model, we introduce three…
A light scalar field, minimally or not-minimally coupled to the metric field, is a well-defined candidate for the dark energy, overcoming the coincidence problem intrinsic to the cosmological constant and avoiding the difficulties of…
We employ a three fluid model in order to construct a cosmological model in the Friedmann Robertson Walker flat spacetime, which contains three types of matter dark energy, dark matter and a perfect fluid with a linear equation of state.…
I describe a new class of quintessence+CDM models in which late time scalar field oscillations can give rise to both quintessence and cold dark matter. Additionally, a versatile ansatz for the luminosity distance is used to reconstruct the…
Aether Scalar-Tensor theory is a relativistic alternative gravity model that behaves like cold dark matter on cosmological scales while predicting the MOND force-law in astrophysical systems. The theory correctly predicts the cosmic…
Gravitational theories with multiple scalar fields coupled to the metric and each other --- a natural extension of the well studied single-scalar-tensor theories --- are interesting phenomenological frameworks to describe deviations from…
Solution generating techniques for general relativity with a conformally (and minimally) coupled scalar field are pushed forward to build a wide class of asymptotically flat, axisymmetric and stationary spacetimes continuously connected to…
We consider the spatially flat Friedmann-Lemaitre-Robertson-Walker space time in the teleparallel model of gravity and assume that the universe is filled nearly by cold dark matter and a nonminimally coupled scalar field with a power-law…
In this work we explore the possibility of incorporating particle physics motivated scalar fields to the dark matter cosmological model. In this landscape, we consider the classical complex scalar field in a certain region in the parameter…