اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدFormation of caustics in Dirac-Born-Infeld type scalar field systems
113
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We investigate the formation of caustics in Dirac-Born-Infeld type scalar field systems for generic classes of potentials, viz., massive rolling scalar with potential, $V(phi)=V_0e^{pm frac{1}{2} M^2 phi^2}$ and inverse power-law potentials with $V(phi)=V_0/phi^n,~0<n<2$. We find that in the case oftexttt{} exponentially decreasing rolling massive scalar field potential, there are multi-valued regions and regions of likely to be caustics in the field configuration. However there are no caustics in the case of exponentially increasing potential. We show that the formation of caustics is inevitable for the inverse power-law potentials under consideration in Minkowski space time whereas caustics do not form in this case in the FRW universe.
قيم البحث
اقرأ أيضاً
In this paper, we investigate novel kinklike structures in a scalar field theory driven by Dirac-Born-Infeld (DBI) dynamics. Analytical features are reached through a first-order formalism and a deformation procedure. The analysis ensures the linear
stability of the obtained solutions, and the deformation method permits to detect new topological solutions given some systems of known solutions. The proposed models vary according to the parameters of the theory. However, in a certain parameter regime, their defect profiles are precisely obtained by standard theories. These are the models relatives. Besides that, we investigate the $beta-$Starobinsky potential in the perspective of topological defects; and we have shown that it can support kinklike solutions, for both canonical and non-canonical kinetics. As a result, we propose two new kinds of generalizations on the $beta-$Starobinsky model, by considering the DBI approach. Finally, we explore the main characteristics of such structures in these new scenarios.
In this paper, we investigate the dynamics of Born-Infeld(B-I) phantom model in the $omega-omega$ plane, which is defined by the equation of state parameter for the dark energy and its derivative with respect to $N$(the logarithm of the scale factor
$a$). We find the scalar field equation of motion in $omega-omega$ plane, and show mathematically the property of attractor solutions which correspond to $omega_phisim-1$, $Omega_phi=1$, which avoid the Big rip problem and meets the current observations well.
We apply the dynamical systems tools to study the (linear) cosmic dynamics of a Dirac-Born-Infeld-type field trapped in the braneworld. We focus,exclusively, in Randall-Sundrum and in Dvali-Gabadadze-Porrati brane models. We analyze the existence and
stability of asymptotic solutions for the AdS throat and the quadratic potential and a particular choice of the warp factor and of the potential for the DBI field ($f(phi)=1/V(phi)$). It is demonstrated, in particular, that in the ultra-relativistic approximation matter-scaling and scalar field-dominated solutions always arise. In the first scenario the empty universe is the past attractor, while in the second model the past attractor is the matter-dominated phase.
The Hawking-Moss tunneling rate for a field described by the Dirac-Born-Infeld action is calculated using a stochastic approach. We find that the effect of the non-trivial kinetic term is to enhance the tunneling rate, which can be exponentially sign
ificant. This result should be compared to the DBI enhancement found in the Coleman-de Luccia case.
We compare the Infrared Dirac-Born-Infeld (IR DBI) brane inflation model to observations using a Bayesian analysis. The current data cannot distinguish it from the LambdaCDM model, but is able to give interesting constraints on various microscopic pa
rameters including the mass of the brane moduli potential, the fundamental string scale, the charge or warp factor of throats, and the number of the mobile branes. We quantify some distinctive testable predictions with stringy signatures, such as the large non-Gaussianity, and the large, but regional, running of the spectral index. These results illustrate how we may be able to probe aspects of string theory using cosmological observations.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
