Dr
Sven Krippendorf
(Physikalisches Institut, University of Bonn)
24/09/2014, 14:00
We present soft supersymmetry breaking terms in type IIB de Sitter string vacua
after moduli stabilisation. We focus on models in which the Standard Model is sequestered from the supersymmetry breaking sources and the spectrum of soft-terms is hierarchically smaller than the gravitino mass.
Mr
Andreas Kapfer
(MPI Munich)
24/09/2014, 14:20
We study partial supersymmetry breaking of five-dimensional N=4 gauged supergravity in consistent truncations ofsupergravity and string theory. Evaluating one-loop Chern-Simons terms we address necessary conditions for consistent truncations to yield also proper effective field theories. As examples we consider SU(2)-structure reduction of M-theory on Calabi-Yau threefolds with vanishing Euler...
Dr
Andreas Deser
(Leibniz University Hannover)
24/09/2014, 15:00
Double field theory is a proposal to incorporate T-duality as a symmetry of a field theory defined on a formally doubled configuration space. Its gauge transformations are governed by the so-called C-bracket which reduces to the Courant bracket of Hitchin and Gualtieri's generalized geometry by solving the "strong constraint", i.e. projecting to a physical configuration space.
By giving an...
Mr
Lorenzo Bianchi
(Humboldt Universität zu Berlin)
24/09/2014, 15:20
Unitarity techniques have proven to be a powerful tool for the computation of scattering amplitudes in three and four dimensions. Here the same method is applied to several massive two-dimensional models, including new results for the world-sheet AdS3×S3xM4 superstring, to compute 2→2 scattering S-matrices at one loop from tree level amplitudes. Evidence is found for a hidden relation with the...
Mrs
Lucila Zárate
(Hämburg University)
24/09/2014, 16:25
We study the phenomenological implications of a string-motivated scenario in which supersymmetry breaking is triggered by the Dilaton field. We show that for the MSSM there is a tension between the expected Higgs mass and the dark matter relic abundance. This constrains the parameter space and thus leads to testable predictions for LHC-14. We also present examples within the general singlet...
Mr
Spyridon Talaganis
(Lancaster University)
24/09/2014, 16:40
Inspired by asymptotically free quantum gravity, we consider a nonlocal scalar field theory toy model that is ghost-free. We consider one-loop and two-loop Feynman diagrams and assess the divergence structure of those diagrams. We discuss the renormalizability of the theory, in contrast with General Relativity (GR). Finally, we indicate how our work will contribute to the establishment of a...
Jonas Reuter
(University of Bonn)
24/09/2014, 17:10
We discuss the minimal gauge group and matter content for all 16 2D reflexive polytopes, where some of these were already discussed in the literature. The polyhedrons are connected by geometric transitions on the geometry side which translates into a toric Higgs branch on the field theory side. This network structure is symmetric and reflects the mirror symmetry of the polytopes.
Mr
Edoardo Vescovi
(Humboldt-Universität zu Berlin)
25/09/2014, 14:00
We compute the null cusp anomalous dimension of ABJM theory at strong coupling up to two-loop order. This is done by evaluating corrections to the corresponding superstring partition function, weighted by the AdS4×CP3 action in AdS light-cone gauge. We compare our result, where we use an anomalous shift in the AdS4 radius, with the cusp anomaly of N=4 SYM, and extract the two-loop contribution...
Dr
Kwang Sik Jeong
(CTPU, IBS)
25/09/2014, 14:20
The QCD axion solving the strong CP problem may originate from antisymmetric tensor gauge fields in compactified string theory, with a decay constant around the GUT scale. Such possibility is in tension with high scale inflation because too large isocurvature perturbations would be generated. A more interesting and still viable possibility is that the string theoretic QCD axion is charged...
Dr
Lukas Witkowski
(Heidelberg University)
25/09/2014, 14:40
The existence of Dark Radiation is a generic prediction of the Large Volume Scenario (LVS), a popular scheme of moduli stabilisation in type IIB string theory. In this talk I will quantify predictions for Dark Radiation for a wide range of LVS models. In particular, I will show that some of the most natural LVS settings with natural values of model parameters lead to Dark Radiation predictions...
Dr
Markus Rummel
(University of Oxford)
25/09/2014, 15:00
We propose an uplift mechanism using a structure of multi-K\"ahler moduli dependence in the F-term potential of type IIB string theory compactifications. This mechanism requires a D-term condition that fixes one modulus to be proportional to another modulus, resulting in a trivial D-term potential. De Sitter minima are realized along with an enhancement of the volume in the Large Volume...
Mr
Richard Galvez
(Syracuse University)
25/09/2014, 15:20
We present preliminary results regarding the validity of inflation being driven by Kahler moduli fields in Calabi-Yau compactifications of arbitrary dimension. By studying the moduli space geometry in the supergravity limit of F-theory constructions, we are able to test the viability of modular inflation in the context of Type IIA/B and M-theory. We end by commenting on a mathematical...
Mr
Mario Galante
(Rijksuniversiteit Groningen)
25/09/2014, 16:10
It is well known that the scalar degrees of freedom of a generic $f(R)$ theory could be recast in a field theory dual using a Weyl scaling of the metric. In this work, we explore how the RG-improved Higgs Inflation model could be seen as a corrected Starobinsky model, showing that the relation between this two models correspond not only to a tree level matching, but at least to a 1-loop level....
Mr
Clemens Wieck
(DESY Hamburg)
25/09/2014, 16:25
We analyze the feasibility of inflation driven by field-dependent FI terms in the presence of an anomalous U(1) symmetry. We consider a heavy Kähler modulus whose axionic component cancels the gauge anomaly via the Green-Schwarz mechanism, i.e., it shifts under the anomalous U(1). The D-term of the modulus may play the role of a field-dependent FI term which can, in principle, drive inflation....
Mr
Takahiro Terada
(The University of Tokyo)
25/09/2014, 16:40
We propose a framework for inflationary model building in supergravity which requires only one chiral superfiled in addition to the standard gravity supermultiplet. A stabilization mechanism for the non-inflaton field in the inflaton supermultiplet is required, for which we take a higher dimensional term in the Kahler potential. This framework allows one to construct a very wide range of...
Prof.
Sergei Ketov
(Tokyo Metropolitan University, Japan)
25/09/2014, 16:55
A novel framework is proposed for embedding the natural inflation into the type IIA superstrings compactified on a Calabi-Yau three-fold. Inflaton is identified with axion of the universal hypermultiplet (UH). The other UH scalars (including dilaton) are stabilized by the CY fluxes whose impact can be described by gauging of the abelian isometry associated with the axion, when the NS5-brane...