Related papers: A Perturbatively Stable Non-Supersymmetric String …
We study ${\cal N}=1$ supergravity with $N>1$ chiral superfields in which one of the fields has a K\"ahler potential of exact no-scale type. Such systems admit de Sitter (dS) solutions in which supersymmetry is predominantly broken by the…
We compute the Kaluza-Klein spectrum of the non-supersymmetric SO(3)$\,\times\,$SO(3)-invariant AdS$_4$ vacuum of 11-dimensional supergravity, whose lowest-lying Kaluza-Klein modes belong to a consistent truncation to 4-dimensional ${\cal…
A general class of deformations of integrable sigma-models with symmetric space F/G target-spaces are found. These deformations involve defining the non-abelian T dual of the sigma-model and then replacing the coupling of the Lagrange…
We address the novel structures arising in quantum and string integrable theories, as well as construct methods to obtain them and provide further analysis. Specifically, we implement the automorphic symmetries on periodic lattice systems…
Scattering amplitudes of the spin-4/3 fractional superstring are shown to satisfy spurious state decoupling and cyclic symmetry (duality) at tree-level in the string perturbation expansion. This fractional superstring is characterized by…
We construct flux-stabilised IIB compactifications whose extra dimensions (EDs) have very different sizes, and use these to describe several vacua with a TeV string scale. Because we can access regimes where 2 dimensions are hierarchically…
We analyze the stability of the moduli at the quantum level in an open-string model realizing the $\mathcal{N}=2\to \mathcal{N}=0$ spontaneous breaking of supersymmetry in four-dimensional Minkowski spacetime. In the region of moduli space…
In this talk, we present three examples of new non-trivial vacuum structures that can occur in supersymmetric field theories, along with explicit models in which they arise. The first vacuum structure is one in which supersymmetry is broken…
In this letter we use a perturbative approach to find the spectrum of non-relativistic strings in the String Newton-Cartan (SNC) AdS$_5\times$S$^5$ spacetime. We perturb the bosonic sector of the action around a BMN-like folded string…
We describe two new types of vacua for ten-dimensional string models without supersymmetry, in which dilaton potentials are compensated by constant electric or magnetic fields. These arise from $\alpha '$ corrections to the equations of…
We investigate the stability and fluctuations of a soft wall model that has an asymptotically AdS metric and a scalar field that has an asymptotically power-law dependence in the conformal coordinate. By imposing UV boundary conditions, the…
We investigate the perturbative and non-perturbative correspondence of a class of four dimensional dual string constructions with N=4 and N=2 supersymmetry, obtained as Z_2 or Z_2 x Z_2 orbifolds of the type II, heterotic and type I string.…
We analyze a class of 5D models where a 3 brane is generated by a bulk scalar field non minimally coupled to gravity. We show that perturbative stability of such branes is normally guaranteed although non minimal couplings are not innocuous…
The spectrum of stable electrically and magnetically charged supersymmetric particles can change discontinuously as one changes the vacuum on the Coulomb branch of gauge theories with extended supersymmetry in four dimensions. We show that…
In addition to the familiar string theories with spacetime supersymmetry, there exist a number of non-supersymmetric ten-dimensional superstrings. Nearly all of these theories have closed string tachyons, indicating a misidentification of…
I construct supersymmetric AdS$_3$ vacua of type IIB string theory that exhibit parametric scale separation in the controlled regime. These solutions arise from compactifications on seven-dimensional manifolds equipped with co-closed…
In this thesis we investigate some aspects of the dramatic consequences of supersymmetry breaking on string vacua. In particular, we focus on the issue of vacuum stability in ten-dimensional string models with broken, or without,…
We consider a possible discretization for the gauge-fixed Green-Schwarz (two-dimensional) sigma-model action for the Type IIB superstring and use it for measuring the cusp anomalous dimension of planar $\mathcal{N}=4$ SYM as derived from…
We study a set of asymmetric deformations of non-critical superstring theories in various dimensions. The deformations arise as Kaehler and complex structure deformations of an orthogonal two-torus comprising of a parallel and a transverse…
Motivated by a possibility of solving non-supersymmetric type 0 string theory in $AdS_5 \times S^5$ background using integrability, we revisit the construction of type 0 string spectrum in some solvable examples of backgrounds with RR…