Stringtheoretische Modelle in Kosmologie und Teilchenphysik

• Applicant: Dr. Michael Haack
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2005 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 15070628

• Final Report Year: 2017

Final Report Abstract

Flux compactifications are by now an indispensable ingredient in most attempts of making contact between string theory and particle physics or cosmology. Several aspects of these compactifications were analyzed. In the context of particle physics it was shown that certain phenomenologically interesting models, known as large volume scenarios, are surprisingly robust towards quantum corrections. Moreover, an issue of gauge invariance of the effective potential in the presence of D7-branes was clarified. In the context of cosmology, an update on brane inflation was given. In particular, it was shown that the inclusion of quantum corrections to the effective inflaton potential in a certain model (known as the D3/D7-brane inflation model) can render it consistent with observation. Further quantum corrections relevant for both particle physics and cosmology were investigated. Another promising approach to phenomenology within string theory is given by the gauge/gravity correspondence. Several results were obtained in this context. There is an interesting class of examples of the gauge/gravity correspondence which describes gauge theories which are not conformal even asymptotically in the ultraviolet. Thus, they constitute a step towards realistic gauge theories compared with the original case of the AdS/CFT correspondence. We managed to calculate the glueball mass spectrum for the prime candidate of this class of gauge theories, the Klebanov-Strassler theory. Furthermore, we devised a method to (holographically) renormalize 2-point functions for these cases. Since some time, the gauge/gravity correspondence at finite temperature and charge density attains a lot of interest, in applications to hydrodynamics and condensed matter systems. In this case, the bulk geometry is given by a black hole in AdS space. This version of the correspondence allows to calculate features of certain strongly coupled fluids (e.g. transport coefficients), which are currently not accessible otherwise. Some results even had some bearing on the interpretation of heavy ion collisions. We obtained transport coefficients for fluids with a gravity dual. This includes the case of charged fluids with anomalies. This led to a surge of interest in the field of anomalous transport. Furthermore, we found an interesting universal relation between three of the higher order transport coefficients which holds for all fluids with a gravity dual at strong coupling. Finally and more recently, we derived first order flow equations for gauged supergravity. The purpose is to find new examples of extremal black solutions which can serve as ground states for the dual field theory.

Publications

• “Gaugino Condensates and D-terms from D7-branes”, JHEP 0701 (2007) 078
  Michael Haack with D. Krefl, D. Lüst, A. Van Proeyen and M. Zagermann
  
• “Jumping Through Loops: On Soft Terms from Large Volume Compactifications”, JHEP 0709 (2007) 031
  Michael Haack with M. Berg and E. Pajer
  
• “Glueballs vs. Gluinoballs: Fluctuation Spectra in non-AdS/non-CFT”, Nucl. Phys. B789 (2008) 1
  Michael Haack with M. Berg and W. Mück
  
• “Nonlinear viscous hydrodynamics in various dimensions using AdS/CFT”, JHEP 0810 (2008) 063
  Michael Haack with A. Yarom
  
• “Fluid dynamics of R-charged black holes”, JHEP 0901 (2009) 055
  Michael Haack with J. Erdmenger, M. Kaminski and A. Yarom
  
• “Universality of second order transport coefficients from the gauge-string duality”, Nucl. Phys. B813 (2009) 140
  Michael Haack with A. Yarom
  
• “Update of D3/D7-Brane Inflation on K3×T2/Z2”, Nucl. Phys. B806 (2009) 103
  Michael Haack with R. Kallosh, A. Krause, A. Linde, D. Lüst and M. Zagermann
  
• “One-Loop Kähler Metric of D-Branes at Angles”, JHEP 1211 (2012) 091
  Michael Haack with M. Berg and J. U. Kang
  
• “Towards the one-loop Kähler metric of Calabi-Yau orientifolds”, JHEP 1412 (2014) 077
  Michael Haack with M. Berg, J. U. Kang and S. Sjörs
  
• “One-loop Einstein-Hilbert term in minimally supersymmetric type IIB orientifolds”, JHEP 1602 (2016) 160
  Michael Haack with J. U. Kang