Related papers: Scanning the Fluxless $G_2$ Landscape
We investigate the universal low-energy dynamics of the simplest Higgs phase for gravity, `ghost condensation.' We show that the nonlinear dynamics of the `ghostone' field dominate for all interesting gravitational sources. Away from…
We construct the first D = 4 Minkowski string theory vacua of flux compactification which are (i) chiral, (ii) free of NSNS and RR tadpoles, and (iii) N = 1 or N = 0 supersymmetric. In the latter case SUSY is softly broken by the fluxes,…
We investigate reductions of M-theory beyond twisted tori by allowing the presence of KK6 monopoles (KKO6-planes) compatible with N=4 supersymmetry in four dimensions. The presence of KKO6-planes proves crucial to achieve full moduli…
The principles of quantum field theory in flat spacetime suggest that gravity is mediated by a massless particle with helicity $\pm2$, the so-called graviton. It is regarded as textbook knowledge that, when the self-coupling of a particle…
We describe how 4d de Sitter vacua might emerge from 11d heterotic M-theory. Non-perturbative effects and $G$-fluxes play a crucial role leading to vacua with F-term supersymmetry breaking and a positive energy density. Charged scalar…
We report on a novel phenomenon of particle cosmology, which features specific cosmological phase transitions via quantum tunnelings through multiple vacua. The latter is inspired by the axiverse ideas and enables us to probe the associated…
In the case of F-theory compactifications on genus-one fibrations without section there are naturally appearing discrete symmetries, which we argue to be associated to geometrically massive U(1) gauge symmetries. These discrete symmetries…
We show that the presence of an anomalous $\rm U_A(1)$ factor in the gauge group of string-derived models may have the new and important phenomenological consequence of allowing the vanishing of ${\rm Str}\,{\cal M}^2$ in the ``shifted"…
We consider the question of asymptotic observables in cosmology. We assume that string theory contains a landscape of vacua, and that metastable de Sitter regions can decay to zero cosmological constant by bubble nucleation. The asymptotic…
We consider compactifications of M-theory on 7-manifolds in the presence of 4-form fluxes, which leave at least four supercharges unbroken. Supersymmetric vacua admit G-structures and we discuss the cases of G_2-, SU(3)- as well as…
Gaugino condensation on D-branes wrapping internal cycles gives a mechanism to stabilize the associated moduli. According to the effective field theory, this gives rise, when combined with fluxes, to supersymmetric AdS$_4$ solutions. In…
We consider the field theory that defines a perfect incompressible 2D fluid. One distinctive property of this system is that the quadratic action for fluctuations around the ground state features neither mass nor gradient term. Quantum…
We discuss phenomenology of quantum vacuum. Phenomenology of macroscopic systems has three sources: thermodynamics, topology and symmetry. Thermodynamics of the self-sustained vacuum allows us to treat the problems related to the vacuum…
We argue that the vast majority of flux vacua with small cosmological constant are unstable to rapid decay to a big crunch. Exceptions are states with large compactification volume and supersymmetric and approximately supersymmetric states.…
An old idea for explaining the hierarchy is strong gauge dynamics. We show that such dynamics {\it also} stabilises the moduli in $M$ theory compactifications on manifolds of $G_2$-holonomy {\it without} fluxes. This gives stable vacua with…
We investigate the possible existence of (meta-)stable de Sitter vacua within N=1 compactifications with generalised fluxes. With the aid of an algorithm inspired by the method of differential evolution, we were able to find three novel…
Quantum vacua are characterized by the topological structure of their fermion zero modes. The vacua are distributed into universality classes protected by topology in momentum space. The vacua whose manifold of fermion zero modes has…
We propose that gravity be intrinsically quantum-mechanical, so that in the absence of quantum mechanics the geometry of the universe would be Minkowski. We show that in such a situation gravity does not require any independent quantization…
We show that the decay of the D2-\bar{D2} system with large worldvolume magnetic fields can be described in noncommutative gauge theory. Tachyon condensation in this system describes the annihilation of D2-\bar{D2} into $D0$-branes. From…
We show how the spectral flow between the Neveu-Schwarz and Ramond sectors of N=2 superconformal field theories can be described in three dimensions in terms of the propagation of charged particles coupled to a a Chern-Simons gauge theory.…