Related papers: Fermionic Tachyons as a Source of Dark Energy
We investigate the cosmological evolution of an interacting phantom energy model in which the phantom field has interaction with the dark matter. We discuss the existence and stability of scaling solutions for two types of specific…
The breakdown of conformal symmetry in a conformally invariant scalar-tensor gravitational model is revisited in the cosmological context. Although the old scenario of conformal symmetry breaking in cosmology containing scalar field has…
The existence of phantom energy in a universe which evolves to eventually show a big rip doomsday is a possibility which is not excluded by present observational constraints. In this letter it is argued that the field theory associated with…
In a recent paper we showed that a quintessence scalar field plus a dissipative matter fluid can drive late cosmic accelerated expansion and simultaneously solve the coincidence problem [1]. In this brief report we extend this result to the…
We consider the cosmological application of Lee-Wick theory where a field has a higher derivative kinetic operators. The higher derivative term can be eliminated by introducing a set of auxiliary fields. We investigate the cosmological…
The main aim of this paper is to present the multi scalar field components as candidates to be the dark energy of the universe and their observational constraints. We start with the canonical Quintessence and Phantom fields with quadratic…
In this paper, we have considered that the universe is filled with tachyon, hessence (or hantom) dark energies. Subsequently we have investigated the interactions between tachyon and hessence (hantom) dark energies and calculated the…
In this work we explore a model of the universe in which dark energy is modelled explicitely with both a dynamical quintessence field (with a double exponential self-interaction potential) and a cosmological constant. For a given region of…
Recent results indicate the presence of a cosmological constant (or related dark energy) in the universe. It has been conjectured recently that the interaction parameters of physical theories may be dependant on the size parameter of the…
In this work a tachyonization of the $\Lambda$CDM model for a spatially flat Friedmann-Robertson-Walker space-time is proposed. A tachyon field and a cosmological constant are considered as the sources of the gravitational field. Starting…
We present a novel source of dark energy, which is motivated by the prevalence of hidden sectors in string theory models and is consistent with all of the proposed swampland conjectures. Thermal effects hold a light hidden sector scalar at…
Mass dimension one fermionic fields are prime candidates to describe dark matter, due to their intrinsic neutral nature, as they are constructed as eigenstates of the charge conjugation operator with dual helicity. To formulate the meaning…
We perform a detailed investigation of interacting phantom cosmology, by applying the powerful method of dynamical system analysis. We consider two well-studied interaction forms, namely one global and one local one, while the novel…
We show that current cosmic acceleration can be explained by an almost massless scalar field experiencing quantum fluctuations during primordial inflation. Provided its mass does not exceed the Hubble parameter today, this field has been…
In this paper we propose a new dark energy model in the teleparallel alternative of general relativity, by considering a generalized non--minimal coupling of a tachyonic scalar field with the teleparallel boundary term. Within the framework…
We present a detailed analysis of the phase-space for the field equations in scalar field cosmology with a chameleon cosmology in a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker spacetime. For the matter source we assume that…
In this article we study the properties of the flat FRW chameleon cosmology in which the cosmic expansion of the Universe is affected by the chameleon field and dark energy. In particular, we perform a detailed examination of the model in…
We demonstrate that a scalar field is unable to reverse its direction of motion while continuously exchanging energy with another fluid. If the rate of transfer is modulated by the scalar's acceleration, the field can undergo a rapid…
The high-quality cosmological data, which became available in the last decade, have thrusted upon us a rather preposterous composition for the universe which poses one of the greatest challenges theoretical physics has ever faced: the…
We analyse theories that do not have a de Sitter vacuum and cannot lead to slow-roll quintessence, but which nevertheless support a transient era of accelerated cosmological expansion due to interactions between a scalar $\phi$ and either a…