相关论文: Bubbles of Nothing and Supersymmetric Compactifica…
We discuss non-perturbative instabilities, mediated by bubbles of nothing, in the context of the AdS/CFT correspondence. By exploring the phase diagram of such decays we give an interpretation of the process in terms of an effective…
We construct a generalization of Witten's Kaluza-Klein instanton, where a higher-dimensional sphere (rather than a circle as in Witten's instanton) collapses to zero size and the geometry terminates at a bubble of nothing, in a low energy…
Supersymmetry breaking and compactification of extra space-time dimensions may have a common dynamical origin if our universe is spontaneously generated in the form of a four-dimensional topological or non-topological defect in higher…
The Standard Model Higgs potential may become unbounded from below at large field values, with important cosmological implications. For a potential of this form, the commonly assumed scenario of a nucleated thin-wall bubble driving the…
We consider the possibility of localizing gravity on a Nielsen-Olesen vortex in the context of the Abelian Higgs model. The vortex lives in a six-dimensional space-time with negative bulk cosmological constant. In this model we find a…
We consider two infinite families of Non-Supersymmetric $AdS_4$ vacua, called Type 2) and Type 3) vacua, that arise in massive IIA supergravity with flux. We show that both families are perturbatively stable. We then examine…
If a theory has more than one classically stable vacuum, quantum tunneling and thermal jumps make the transition between the vacua possible. The transition happens through a first order phase transition started by nucleation of a bubble of…
We use a field theoretic generalization of the Wigner-Weisskopf method to study the stability of the Bunch-Davies vacuum state for a massless, conformally coupled interacting test field in de Sitter space. We find that in $\lambda \phi^4$…
At the leading order, M-theory admits minimal supersymmetric compactifications if the internal manifold has exceptional holonomy. Once we take into account higher order quantum correction terms in the low energy effective action, the…
In this thesis, we study moduli in compactifications of ten-dimensional heterotic supergravity. We consider supersymmetric compactifications to four-dimensional maximally symmetric space, commonly referred to as the Strominger system. The…
We consider warped compactifications in (4+d)-dimensional theories, with four dimensional de Sitter dS_4 vacua (with Hubble parameter H) and with a compact internal space. After introducing a gauge-invariant formalism for the generic metric…
This paper is mainly concerned with the free boundary problem for an approximate model (for example, arising from the study of sonoluminescence) of a gas bubble of finite mass enclosed within a bounded incompressible viscous liquid,…
We re-examine the problem of vacuum decay in the presence of spherically symmetric black holes. Within the semiclassical approximation, we study configurations describing a bubble of true vacuum propagating outside a black hole formed from…
We study moduli stabilization in the context of M-theory on compact manifolds with G2 holonomy, using superpotentials from flux and membrane instantons, and recent results for the Khaeler potential of such models. The existence of minima…
We investigate non-perturbative structures of the two-dimensional N=2 supersymmetric nonlinear sigma model on the quadric surface Q^{n-2}(C) = SO(n)/SO(n-2)xU(1), which is a Hermitian symmetric space, and therefore Kahler, by using the…
We find a cosmological solution corresponding to compactification of 10d supergravity on a warped conifold that easily circumvents `no-go' theorem given for a warped/flux compactification, providing new perspectives for the study of…
We prove the absence of a mass gap and confinement in the Polyakov model with massless complex fermions in any representation of the gauge group. A $U(1)_{*}$ topological shift symmetry protects the masslessness of one dual photon. This…
The present paper considers a homogeneous bubble inside an unbounded polytropic compressible liquid with viscosity. The system is governed by the Navier-Stokes equation with free boundary which is determined by the kinematic and dynamic…
We extend the `topological inflation' of Linde and Vilenkin to {\em unstable} monopoles. This allows the monopole to decay; not inflating eternally, as topological inflation demands. Such a situation happens naturally in some Grand Unified…
In this paper, we present a series of supersymmetric models exhibiting an entirely new vacuum structure: towers of metastable vacua with higher and higher energies. As the number of vacua grows towards infinity, the energy of the highest…