Winding string condensation and noncommutative deformation of a spacelike singularity

Abstract

In a previous paper (hep-th/0509067) using matrix model, we showed that closed string tachyons can resolve spacelike singularity in one particular class of Misner space (with anti-periodic boundary conditions for fermions around the spatial circle). In this note, we show that for Misner space without closed string tachyons, there also exists a mechanism to resolve the singularity in the context of the matrix model, namely cosmological winding string production. We show that here space and time also become noncommutative due to these winding strings. Employing optical theorem, we study the bulk boundary coupling by calculating the four-open-string cylinder amplitudes.

Parameter Space of Quiver Gauge Theories

“…In order to do this we will first discuss the quiver for a brane/anti-brane pair. 9 Basically the massless open strings between such a pair gives rise to a set of fields and ghost fields which cancel each other precisely. The field/ghost field pairs can then be used to rearrange the degrees of freedom in a quiver to a dual quiver.…”

“…(4.1) 9 The idea of adding an anti-brane has also been considered in [43]. However our treatment of the open string modes will be rather different 10 Other examples of systems without physical excitations are the bcβγ quartets in two-dimensional CFT.…”

“…Relations between quivers and non-commutative Calabi-Yau spaces have previously been pursued in the series of papers [6][7][8][9]. Other aspects of exceptional collections have recently been explored in [10][11][12].…”

Effective dynamics of the matrix big bang

“…Our goal in this work is to study the dynamics of the particular Big Bang model introduced in [2] based on Matrix theory [3]. For a sampling of recent work on holography and cosmological singularities, see [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The space-time theory is type IIA string theory in flat space with a non-trivial dilaton,…”

A one loop problem of the matrix big bang model

“…This model was subsequently generalized to a class of more general backgrounds in [2], and to a class of even more general backgrounds in [3], [4], and [5] (a concrete model in this class was previously studied in detail in [6]). For related work on time-dependent backgrounds, see [7], [8], [9], and [10].…”