Electric S-brane solutions corresponding to rank-2 Lie algebras: acceleration and small variation of G

TL;DR

This paper explores electric S-brane solutions linked to rank-2 Lie algebras, demonstrating a period of accelerated expansion of our universe with minimal variation in the gravitational constant G, influenced by scalar fields and brane intersections.

Contribution

It introduces new S-brane solutions associated with Lie algebras A_2, C_2, and G_2, analyzing their impact on cosmic acceleration and G's variation.

Findings

Existence of a time interval with accelerated expansion and small G variation.

Near the minimum of G(τ), the variation decreases in the order A_2, C_2, G_2.

Solutions involve scalar fields and brane intersection rules corresponding to specific Lie algebras.

Abstract

Electric S-brane solutions with two non-composite electric branes and a set of l scalar fields are considered. The intersection rules for branes correspond to Lie algebras A_2, C_2 and G_2. The solutions contain five factor spaces. One of them, M_0, is interpreted as our 3-dimensional space. It is shown that there exists a time interval where accelerated expansion of our 3-dimensional space is compatible with a small enough variation of the effective gravitational constant G(\tau). This interval contains \tau_0, a point of minimum of the function G(\tau). A special solution with two phantom scalar fields is analyzed and it is shown that in the vicinity of the point \tau_0 the time variation of G(\tau) (calculated in the linear approximation) decreases in the sequence of Lie algebras A_2, C_2 and G_2.