The effects of inhomogeneities on the cosmology of type IIB conifold transitions

Abstract

In this paper we examine the evolution of the effective field theory describing a conifold transition in type IIB string theory. Previous studies have considered such dynamics starting from the cosmological approximation of homogeneous fields , here we include the effects of inhomogeneities by using a real-time lattice field theory simulation. By including spatial variations we are able to simulate the effect of currents and the gauge fields which they source. We identify two different regimes where the inhomogeneities have opposite effects, one where they aid the system to complete the conifold transition and another where they hinder it. The existence of quantized fluxes in related systems has lead to the speculation that (unstable) string solutions could exist, using our simulations we give strong evidence that these string-like defects do not form. § 1 There might be a possibility of having confinement for semilocal-like string solutions for finite strings [19].

Singular manifolds, topology change and the dynamics of compactification

“…Other transitions may change the Hodge numbers, such as a conifold transition [4,5] where an S 2 collapses and reappears as an S 3 , see also [5]. Again, such a singular transformation can be made regular within string theory [12], and the corresponding low-energy theory may be studied [13] along with its dynamics [14,15].…”

“…In this paper we study the dynamics of the resolved spaces while the cycles are collapsing. Unlike previous studies on the dynamics of such spaces [9,10,11,14,15] we are particularly interested in the gravitational properties of collapsing cycles; more specifically, whether a horizon forms as the cycle becomes small. Should a horizon form in the higher dimensional theory, then this would render the low-energy theory based on the moduli fields inapplicable near the conical singularity, implying that the dynamics of topology changing processes is more complicated than simply studying the dynamics of the moduli fields in the low-energy description.…”

The gravitational dynamics of warped throats

“…Such a change to the topology could be a very drastic process, altering intersection numbers or even the Hodge numbers of the compact topology. These transitions can be made regular, and their low energy dynamics studied within the realm of string theory [8,9,10,11]. The range of possible vacuum topology and moduli is collectively called the string landscape [12] and our own position within this huge range of vacua will determine many of the phenomenological predictions of the construction.…”

The evolution of conifolds

“…Remarkably, string theory is able to make sense of these singular geometries by the appearance of new light states corresponding to D-branes wrapping the collapsing cycles [7]. We can also investigate the low energy theory [8] and deduce its dynamics [9,10,11,12,13]. The singular geometry has acted to connect the moduli spaces, its singularity is conical and takes the local description of a discrete quotient of a smooth manifold X, X = X/Γ, where Γ is a finite symmetry group; the singularity is then the fixed point set of Γ.…”