Cosmic Acceleration from M Theory on Twisted Spaces

TL;DR

This paper explores how twisted compactifications in supergravity can produce scalar potentials with positive minima, leading to accelerated expansion in four-dimensional cosmology, extending previous solutions and relating them to multi-scalar exponential models.

Contribution

It introduces new cosmological solutions from twisted supergravity compactifications and connects these to multi-scalar exponential potential models.

Findings

Existence of local minima with positive vacuum energy in scalar potentials.

New examples of accelerating cosmologies from twisted product spaces.

Relation between asymptotic multi-scalar solutions and twisted compactification models.

Abstract

In a recent paper [I.P. Neupane and D.L. Wiltshire, Phys. Lett. B 619, 201 (2005).] we have found a new class of accelerating cosmologies arising from a time--dependent compactification of classical supergravity on product spaces that include one or more geometric twists along with non-trivial curved internal spaces. With such effects, a scalar potential can have a local minimum with positive vacuum energy. The existence of such a minimum generically predicts a period of accelerated expansion in the four-dimensional Einstein-conformal frame. Here we extend our knowledge of these cosmological solutions by presenting new examples and discuss the properties of the solutions in a more general setting. We also relate the known (asymptotic) solutions for multi-scalar fields with exponential potentials to the accelerating solutions arising from simple (or twisted) product spaces for internal manifolds.