String theory is a promising solution for a profound problem: How does everyday gravitation behave on the short distance scales where the phenomena of quantum physics become noticeable?
In the basic approach of string theory, the fundamental objects of physics are no longer point-like particles but rather one-dimensional objects, so-called strings.
It appears that the strings move through a ten-dimensional space-time and must be supersymmetrical there. This assumption has many consequences: for example, that besides the strings there are also higher-dimensional objects, so-called D-branes.
A central question is how our familiar four-dimensional space-time, with the physics known to us, can be derived from this higher-dimensional theory.
In this context, the string theory group at the MPP is engaged with a number of different "compactification" scenarios, such as F-theory, for example. At the same time, the theorists are investigating what implications these have for particle physics and cosmology.
Further, they are studying the quantum properties of black holes and the structure of quantum scattering processes in quantum field theory and quantum gravitation as well as the mathematical properties of compactifications, and non-associative algebras in particular.
In addition, there are surprising relationships in string theory between different physical theories, so-called dualities. One of these dualities, the AdS/CFT correspondence, posits a relationship between gravitational theory and quantum field theory. AdS stands for "anti-de Sitter space," and CFT for conformal field theory. With this, MPP scientists are establishing new connections between string theory and the physics of the strong interaction, which is dominant between quarks and gluons.
X. Bekaert, J. Erdmenger, D. Ponomarev and C. Sleight,
Quartic AdS Interactions in Higher-Spin Gravity from Conformal Field Theory
Journal of High Energy Physics 1511 (2015) 149
R. Blumenhagen, A. Font, M. Fuchs, D. Herschmann, E. Plauschinn, Y. Sekiguchi, F. Wolf
"A Flux-Scaling Scenario for High-Scale Moduli Stabilization in String
Theory", Nucl.Phys. B897 (2015) 500-554
G. Dvali, C. Gomez, R. Isermann, D. Lüst, S. Stieberger
Black Hole Formation and Classicalization in ultra-Planckian 2 -> N Scattering
Nucl.Phys. 893 (2015) 187
A. Font, I. Garcia Etxebarria, D. Lüst, S. Massai, C. Mayrhofer
Heterotic T-fects, 6D SCFTs and F-Theory