Related papers: O(N) quintessence
We study the Non-Linear Born-Infeld(NLBI) scalar field model and quintessence model with two different potentials($V(\phi)=-s\phi$ and ${1/2}m^2\phi^2$). We investigate the differences between those two models. We explore the equation of…
We show that the CPN model with odd number of scalar fields and V-shaped potential possesses finite energy compact solutions in the form of Q-balls and Q-shells. The solutions were obtained in 3+1 dimensions. Q-balls appears for N=1 and N=3…
We study dynamics of flat directions in the minimal supersymmetric standard model taking account of its constituent fields. It is found that there exist new instabilities due to the D-term potential and the nature of these instabilities…
We study the energy-momentum tensor of stable, meta-stable and unstable Q-balls in scalar field theories with U(1) symmetry. We calculate properties such as charge, mass, mean square radii and the constant d1 ("D-term") as functions of the…
The value of scalar field coupled to gravity should be less than the Planck scale in the consistent theory of quantum gravity. It provides a theoretic constraint on the equation of state parameter for the quintessence. In some cases our…
Within present constraints on the observed smooth energy and its equation of state parameter, it is important to find out whether the smooth energy is static (cosmological constant) or dynamic (quintessence). The most dynamical quintessence…
The de Sitter conjecture yields a severe bound on possible vacua for a consistent quantum gravity. We extend the de Sitter conjecture by taking into account dynamics of the scalar field. We then apply such an extended de Sitter conjecture…
We consider the evolution and decay of Q-balls under the influence of quantum fluctuations. We argue that the most important effect resulting from these fluctuations is the modification of the effective potential in which the Q-ball…
We add a new scalar field in the no-scale Brans-Dicke gravity and require it to have a global O(2) symmetry with the original scalar field in the Brans-Dicke gravity. This gives us a new massless scalar field in the Einstein frame due to…
We review that in perturbative string theory, flat, homogeneous and isotropic cosmological evolutions found in no-scale models at the quantum level can enter into "quantum no-scale regimes" (QNSRs). When this is the case, the quantum…
Q-balls are large bound-state systems of scalar particles, described classically through localized solutions of the equations of motion. Promoting the required stabilizing $U(1)$ symmetry to a gauge symmetry leads to gauged Q-balls, which…
Scalar fields which carry charge can generally form non-topoligical solitons (Q-balls), if the energy in the extended configuration is less than the energy of an equivalent number of free quanta. For global Q-balls, such solitons exist…
In this paper we study a quintessence scalar field in a potential exponentially decreasing with e-folding number, and show that the universe is currently undergoing an accelerated expansion and could probably remain accelerating…
In this paper the existence of analytical solutions describing $Q$-balls in a family of deformed $O(4)$ sigma models in (1+1) dimensions has been investigated. These models involve two complex scalar fields whose coupling breaks the $O(4)$…
We study the change of the effective fine structure constant in the cosmological models of a scalar field with a non-vanishing coupling to the electromagnetic field. Combining cosmological data and terrestrial observations we place…
In quintessence scalar field theories, the presence of scaling solutions are important during the radiation and matter epoch due to having their attractor character. Usually, it is assumed that the initial conditions of the quintessence…
Q-balls are non-topological solitons in field theories whose stability is typically guaranteed by the existence of a global conserved charge. A classic realization is the Friedberg-Lee-Sirlin (FLS) Q-ball in a two-scalar system where a real…
An alternative to a cosmological constant is quintessence, defined as a slowly-varying scalar field potential V(\phi). If quintessence is observationally significant, an epoch of inflation is beginning at the present epoch, with \phi the…
We investigate the Q-ball formation in the thermal logarithmic potential by means of the lattice simulation, and reconfirm qualitatively the relation between Q-ball charge and the amplitude of the Affleck-Dine field at the onset of its…
We study $Q$-ball type solitons in arbitrary spatial dimensions in the setting recently described by Kusenko, where the scalar field potential has a flat direction which rises much slower than $\phi^2$. We find that the general formula for…