A New Global 1-form in Lyra Geometric Cosmos Model

Abstract

Dark energy phenomena has inspired lots of investigations on the cosmological constant problems. In order to understand its origin and properties as well as its impacts on universe's evolutions, there are many approaches to modify the well-known General Relativity, such as the Weyl-Lyra Geometry. In the well studied cosmology model within Lyra geometry, there is a problem that the first law of thermodynamics is violated. To unravel this issue, if we use the effective density and pressure in the Lyra cosmology model to preserve the first law of thermodynamics in the cosmos, the former 1-form (β, 0, 0, 0) cannot give a proper vacuum behavior. In this paper, the auxiliary 1-form is modified to overcome this difficulty. It can be shown that the complex terms in the field equation derived from the regime of Lyra Geometric 3 2 φ µ φν − 3 4 δ µ ν φ α φαwith our new 1-form could behave just as the cosmological constant. This work can be regarded as a new exploration on a possible origin of the cosmological constant from a Lyra cosmology model. PACS numbers :98.80.-k 98.80.Qc

Behavior of a vacuum and naked singularity under a smooth gauge function in Lyra geometry

“…(Note that x 0 is merely the symbol represents the gauge function following historical convention and has nothing to do with the time component of the spacetime coordinate.) Recently, many interesting theoretical topics in Lyra geometry have been widely discussed, like the singularity in a collapsing massive star [11], cosmology models in Lyra geometry [10,12,14,[18][19][20], gauge field as the source of gravity [7,13,16,17], so on and so forth. In this article, after we choose a series of smooth and spherically symmetric gauge functions, singularities emerge at r = 0.…”

On Exact Cosmological Models of a Scalar Field in Lyra Geometry

“…[10][11][12][13][14][15][16][17][18]). A number of interesting results have been obtained when accounting for the effective cosmological term in Lyra geometry [19][20][21][22][23][24]. Recall that the displacement vector field has a purely geometrical origin.…”

On Exact Cosmological Models of a Scalar Field in Lyra Geometry

“…[10][11][12][13][14][15][16][17][18]). A number of interesting results have been obtained when accounting for the effective cosmological term in Lyra geometry [19][20][21][22][23][24]. Recall that the displacement vector field has a purely geometrical origin.…”