8,251 research outputs found
The importance of scalar fields as extradimensional metric components in Kaluza-Klein models
Extradimensional models are achieving their highest popularity nowadays,
among other reasons, because they can plausible explain some standard cosmology
issues, such as the cosmological constant and hierarchy problems. In
extradimensional models, we can infer that the four-dimensional matter rises as
a geometric manifestation of the extra coordinate. In this way, although we
still cannot see the extra dimension, we can relate it to physical quantities
that are able to exert such a mechanism of matter induction in the observable
universe. In this work we propose that scalar fields are those physical
quantities. The models here presented are purely geometrical in the sense that
no matter lagrangian is assumed and even the scalar fields are contained in the
extradimensional metric. The results are capable of describing different
observable cosmic features and yield an alternative to ultimately understand
the extra dimension and the mechanism in which it is responsible for the
creation of matter in the observable universe
Configurational entropy in brane models
In this work we investigate generalized theories of gravity in the so-called
configurational entropy (CE) context. We show, by means of this
information-theoretical measure, that a stricter bound on the parameter of
brane models arises from the CE. We find that these bounds are
characterized by a valley region in the CE profile, where the entropy is
minimal. We argue that the CE measure can open a new role and an important
additional approach to select parameters in modified theories of gravitation
False Vacuum Transitions - Analytical Solutions and Decay Rate Values
In this work we show a class of oscillating configurations for the evolution
of the domain walls in Euclidean space. The solutions are obtained
analytically. Phase transitions are achieved from the associated fluctuation
determinant, by the decay rates of the false vacuum.Comment: 6 pages, improved to match the final version to appear in EP
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