Jose Edgar Madriz Aguilar

Stochastic gravitoelectromagnetic inflation

Abstract Gravitoelectromagnetic inflation was recently introduced to describe, in an unified manner, electromagnetic, gravitatory and inflaton fields in the early (accelerated) inflationary universe from a 5D vacuum state. In this Letter, we study a stochastic treatment for the gravitoelectromagnetic components A B = ( A μ , φ ) , on cosmological scales. We focus our study on the seed magnetic fields on super-Hubble scales, which could play an important role in large scale structure formation of the universe.

Modified Brans-Dicke theory of gravity from five-dimensional vacuum

We investigate, in the context of five-dimensional (5D) Brans–Dicke theory of gravity, the idea that macroscopic matter configurations can be generated from pure vacuum in five dimensions, an approach first proposed by Wesson and collaborators in the framework of 5D general relativity. We show that the 5D Brans–Dicke vacuum equations when reduced to four dimensions (4D) lead to a modified version of Brans–Dicke theory in 4D. As an application of the formalism, we obtain two 5D extensions of 4D O’Hanlon and Tupper vacuum solution and show that they lead two different cosmological scenarios in 4D.

ON WEYL COSMOLOGY IN FIVE DIMENSIONS AND THE COSMOLOGICAL CONSTANT

In this talk notes we expose the possibility to induce the cosmological constant from extra dimensions from a geometrical framework where our four-dimensional Riemannian spacetime is embedded into a five-dimensional Weyl integrable space. In particular following the approach of the induced matter theory (IMT) we show that when we go down from five to four dimensions we may recover the induced energy momentum tensor of the IMT plus a cosmological constant term that is determined by the presence of the Weyl scalar field on the bulk.

Passing to an effective 4D phantom cosmology from 5D vacuum theory of gravity

Starting from a five-dimensional (5D) vacuum theory of gravity where the extra coordinate is considered as non-compact, we investigate the possibility of inducing four-dimensional (4D) phantom scenarios by applying form-invariance symmetry transformations. In particular we obtain phantom scenarios for two cosmological frameworks. In the first framework we deal with an induced 4D de Sitter expansion and in the second one a 4D induced model where the expansion of the universe is dominated by a decreasing cosmological parameter Λ(t) is discussed.

Gravitational waves generated during inflation from a 5D vacuum theory of gravity in a de Sitter expansion

In this Letter we study the generation of gravitational waves during inflation from a 5D vacuum theory of gravity. Within this formalism, on an effective 4D de Sitter background, we recover the typical results obtained with 4D inflationary theory in general relativity, for the amplitude of gravitational waves generated during inflation. We also obtain a range of values for the amplitude of tensor to scalar ratio which is in agreement with COBE observations.

Gravitational waves during inflation in presence of a decaying cosmological parameter from a 5D vacuum theory of gravity

We study gravitational waves generated during the inflationary epoch in presence of a decaying cosmological parameter on a 5D geometrical background which is Riemann flat. Two examples are considered, one with a constant cosmological parameter and the second with a decreasing one.

Inflation from the bang of a white hole induced from a 6D vacuum state

Abstract Using ideas of STM theory, but starting from a 6D vacuum state, we propose an inflationary model where the universe emerges from the blast of a white hole. Under this approach, the expansion is affected by a geometrical deformation induced by the gravitational attraction of the hole, which should be responsible for the k R -non invariant spectrum of galaxies (and likewise of the matter density) today observed.

Inducing a Modified Brans–dicke Theory of Gravity From Five-dimensional Vacuum

In these notes of our talk we present an analysis, in the context of five-dimensional (5D) Brans–Dicke theory of gravity, of the idea that macroscopic matter configurations can be generated from pure vacuum in 5D following in much the approach first proposed by Wesson collaborators of the induced matter theory (IMT). We show that it is possible to induce a modified Brans–Dicke theory of embedded four-dimensional (4D) spacetime. Using this formalism we obtain two 5D extensions of the known 4D O’Hanlon vacuum solution and we show that they lead to two different cosmological scenarios on the 4D spacetime.