Studies in String Cosmology

ISBN-13: 9783639080193 / Angielski / Miękka / 2008 / 276 str.

Amanda Weltman

Opis

In this book we study the problem of moduli stabilisation in a cosmological context of string theory. Motivated by the moduli stabilisation problem, we introduce for the first time chameleon fields, so named because their masses and values depend sensitively on the local matter density. We show that such fields can evade all local tests of the equivalence principle and we make predictions for near-future tests of gravity in space while driving the current phase of cosmic accelerated expansion. We then study string corrections to racetrack inflation, a proposal for inflationary dynamics in the context of flux compactifications. Finally, we study a truncated low energy effective action that models the neighbourhood of special points in moduli space, such as conifold points, where extra massless degrees of freedom arise. We study moduli dynamics and stabilisation in this context in a cosmological background and find surprising variety in field dynamics including the appearance of chaos. The chaos aids in our understanding of the behaviour of moduli near these special points. In particular we find a viable mechanism for trapping some of the moduli near these points.

O autorze

Dr. Weltman, daughter of Ivan and Sheina Weltman, grew up in
Johannesburg and Cape Town, South Africa. In 2007 she completed
her PhD at Columbia University under the supervision of Professor
Brian Greene. After a postdoc at Cambridge University, she is
currently faculty at the University of Cape Town, where she
completed her undergraduate studies.