Higher order corrections to Heterotic M-theory inflation

We investigate inflation driven by $N$ dynamical five-branes in Heterotic M-theory using the scalar potential derived from the open membrane instanton sector. At leading order the resulting theory can be mapped to power law inflation, however more generally one may expect higher order corrections to be important. We consider a simple class of such corrections, which imposes tight bounds on the number of branes required for inflation.Comment: 10 pages, 2 figure

Non-standard embedding and five-branes in heterotic M-Theory

We construct vacua of M-theory on S^1/Z_2 associated with Calabi-Yau three-folds. These vacua are appropriate for compactification to N=1 supersymmetry theories in both four and five dimensions. We allow for general E_8 x E_8 gauge bundles and for the presence of five-branes. The five-branes span the four-dimensional uncompactified space and are wrapped on holomorphic curves in the Calabi-Yau space. Properties of these vacua, as well as of the resulting low-energy theories, are discussed. We find that the low-energy gauge group is enlarged by gauge fields that originate on the five-brane world-volumes. In addition, the five-branes increase the types of new E_8 x E_8 breaking patterns allowed by the non-standard embedding. Characteristic features of the low-energy theory, such as the threshold corrections to the gauge kinetic functions, are significantly modified due to the presence of the five-branes, as compared to the case of standard or non-standard embeddings without five-branes.Comment: 34 pages, Latex 2e with amsmath, typos removed, factors corrected, refs improve

The Universe as a domain wall

It is shown that the effective five-dimensional theory of the strongly coupled heterotic string is a gauged version of N = 1 five-dimensional supergravity with four-dimensional boundaries. For the universal supermultiplets, this theory is explicitly constructed by a generalized dimensional reduction procedure on a Calabi-Yau manifold. A crucial ingredient in the reduction is the retention of a “non-zero mode” of the four-form field strength, leading to the gauging of the universal hypermultiplet by the graviphoton. We show that this theory has an exact three-brane domain wall solution which reduces to Witten’s “deformed” Calabi-Yau background upon linearization. This solution consists of two parallel three-branes with sources provided by the four-dimensional boundary theories and constitutes the appropriate background for a reduction to four dimensions. Four-dimensional space-time is then identified with the three-brane world volume

Heterotic M-theory vacua with five-branes

We construct vacua of heterotic M-theory with general gauge bundles and five-branes. Some aspects of the resulting low-energy effective theories are discussed