Related papers: Generating Small Numbers by Tunneling in Multi-Thr…
The simplest toroidally compactified string theories exhibit a duality between large and small radii: compactification on a circle, for example, is invariant under R goes to 1/R. Compactification on more general Lorentzian lattices (i.e.…
We use path-integrals to derive a general expression for the semiclassical approximation to the partition function of a one-dimensional quantum-mechanical system. Our expression depends solely on ordinary integrals which involve the…
Unitarity implies that the evaporation of microscopic quasi-classical black holes cannot be universal in different particle species. This creates a puzzle, since it conflicts with the thermal nature of quasi-classical black holes, according…
If our 3+1-dimensional universe is a brane or domain wall embedded in a higher dimensional space, then a phenomenon we term the ``clash of symmetries'' provides a new method of breaking some continuous symmetries. A global $G_{\text{cts}}…
We study universality of geometric gauge sectors in the string landscape in the context of F-theory compactifications. A finite time construction algorithm is presented for $\frac43 \times 2.96 \times 10^{755}$ F-theory geometries that are…
We construct charged black branes in type IIA flux compactifications that are dual to (2+1)-dimensional field theories at finite density. The internal space is a general Calabi-Yau manifold with fluxes, with internal dimensions much smaller…
In the Cosmological Slingshot Scenario, our Universe is a D3-brane that extends in the 4d noncompact directions of a warped Calabi-Yau compactification of IIB Supergravity. Early time cosmology corresponds to a period in which the brane…
Localised sources such as D-branes or orientifold planes play an important role in many string compactifications that are relevant for phenomenology. The presence of these objects typically induces complicated dynamics in the compact…
We investigate in some quantitative details the viability of reheating in multi-throat brane inflationary scenarios by estimating and comparing the time scales for the various processes involved. We also calculate within perturbative string…
We analyse the dynamics of a probe D3-(anti-)brane propagating in a warped string compactification, making use of the Dirac-Born-Infeld action approximation. We also examine the time dependent expansion of such moving branes from the…
In the context of colliding brane worlds I discuss a toy cosmological model, developed in collaboration with E. Gravanis, which arguably produces inflation and a relaxing to zero cosmological ``constant'' hierarchically small as compared to…
Solitonic brane cosmologies are found where the world-volume is curved due to the evolution of the dilaton field on the brane. In many cases, these may be related to the solitonic Dp- and M5-branes of string and M-theory. An…
Mechanism for generation of suppressed neutrino masses, within low scale theories, is considered. The mechanism do not have extradimensional nature and is realized through extended $SU(2)_L$ scalar multiplets. Latters, in some cases, are…
String theory suggests that black hole microstates are quantum, horizon sized `fuzzballs', rather than smooth geometries with horizon. Radiation from fuzzballs can carry information and does not lead to information loss. But if we let a…
Symmetry Theories (SymThs) provide a flexible framework for analyzing the global categorical symmetries of a $D$-dimensional QFT$_{D}$ in terms of a $(D+1)$-dimensional bulk system SymTh$_{D+1}$. In QFTs realized via local string…
The phenomenon of real-space condensation is encountered in a variety of situations such as aggregation and fragmentation processes, granular clustering, phase separation, traffic and networks. Unlike traditional Bose-Einstein condensation…
Recently there has been an increasing interest in the study of generalized symmetries in dimensions higher than two. This has lead to the discovery of various manifestations of generalized symmetries, notably higher-group and non-invertible…
A new mechanism of tunnelling at macroscopic distances is proposed for a wave packet localized in one-dimensional disordered potential with mirror symmetry, V(-x)=V(x). Unlike quantum tunnelling through a regular potential barrier, which…
We continue the investigation of symmetries and anomalies of $T[M]$ theories obtained by compactifying 6d SCFTs on an internal manifold $M$. We extend the notion of "polarizations on a manifold $M$" to cases where $M$ may have boundaries or…
In cold dark matter cosmological models, structures form and grow by merging of smaller units. Numerical simulations have shown that such merging is incomplete; the inner cores of halos survive and orbit as "subhalos" within their hosts.…