Field dynamics and tunneling in a flux landscape

Abstract

We investigate field dynamics and tunneling between metastable minima in a landscape of Type IIB flux compactifications, utilizing monodromies of the complex structure moduli space to continuously connect flux vacua. After describing the generic features of a flux-induced potential for the complex structure and Type IIB axio-dilaton, we specialize to the Mirror Quintic Calabi-Yau to obtain an example landscape. Studying the cosmological dynamics of the complex structure moduli, we find that the potential generically does not support slow-roll inflation and that in general the landscape separates neatly into basins of attraction of the various minima. We then discuss tunneling, with the inclusion of gravitational effects, in many-dimensional field spaces. A set of constraints on the form of the Euclidean paths through field space are presented, and then applied to construct approximate instantons mediating the transition between de Sitter vacua in the flux landscape. We find that these instantons are generically thick-wall and that the tunneling rate is suppressed in the large-volume limit. We also consider examples where supersymmetry is not broken by fluxes, in which case near-BPS thin-wall bubbles can be constructed. We calculate the bubble wall tension, finding that it scales like a D-or NS-brane bubble, and comment on the implications of this correspondence. Finally, we present a brief discussion of eternal inflation in the flux-landscape.

Analyzing multifield tunneling with exact bounce solutions

“…We may also check the scaling of the approximation/ lower bound (5). Naming this quantity S LB , we observe that it scales as S LB g ¼ g 4b−a S LB , which is the same as the bounce action.…”

“…The string theory landscape motivates the study of multifield potentials with a large number of metastable vacua [1][2][3][4][5][6][7][8][9][10][11]. Since our Universe may have occupied a metastable vacuum in the past or may do so today, it is of cosmological interest to study tunneling out of metastable vacua [12][13][14][15][16][17][18][19][20].…”

Mirror quintic vacua: hierarchies and inflation

“…In [38,39] the authors studied minima using monodromies in the mirror quintic and looked at the non-perturbative stability and inflation in the complex structure and axio-dilaton sector. We study the periods around the conifold as in [37], but do this up to a higher order in the series expansion in z, until convergence is achieved in the search for vacua and inflationary regions.…”

Tumbling through a landscape: Evidence of instabilities in high-dimensional moduli spaces

“…Yet, tunneling trajectories in multidimensional field spaces are notoriously subtle and can exhibit unexpected features; explicit examples in the landscape are the conifunneling trajectories between monodromyrelated flux vacua found in [25] (see also [26,27]). An additional, and potentially pivotal, complication is that the different flux vacua that are not monodromy related are generally minima of distinct potentials.…”