Scales and Cosmological Applications of M Theory
Karim Benakli
TL;DR
The paper surveys scale hierarchies, dark matter candidates, and cosmological solutions within Hořava–Witten M-theory compactifications. It analyzes how Calabi–Yau volumes and the S^1/Z_2 interval shape observable and hidden sectors, employing an expansion in ρ M11^{-3}/V^{2/3} to relate M_GUT, G_N, and gauge couplings. It then discusses dark matter possibilities on the hidden wall or in the bulk, and presents a method to generate cosmological solutions from p-brane backgrounds, including a nucleation picture and potential AdS-ending cosmologies. Together, these results illuminate how higher-dimensional M-theory frameworks could imprint testable low-energy phenomenology and cosmological behavior, while highlighting model dependencies and the need for further concrete constructions.
Abstract
I review recent results in three topics of the M-world: (i) Scales. (ii) New dark matter candidates. (iii) Cosmological solutions from p-branes. The three topics are discussed in the framework of Hořava-Witten compactifications. Part (iii) includes comments on cosmological solutions in M-theory describing nucleation of universes through instanton effects and expansions toward asymptotically flat or anti-de-Sitter spaces.