Physics Beyond the Standard Model
My main interests are theories beyond the Standard Model. I am especially interested in different approaches to Quantum Gravity and their phenomenology, like the occurrence of a minimal length scale as UVregulator, extra dimensions, modifications of Lorentzinvariance, the generalized uncertainty principle, quantum fields in curved spacetime and black holes physics. I find it promising to examine interrelationships between these topics, and I strive to develop models that are useful to directly test a given assumption. In this context, brane world scenarios are an intriguing subject which relates String Theory to existing effective models and allow us to approach a variety of topics: from the fermion mass hierarchies, over the mechanism of symmetry breaking to black holes and cosmology. Besides the string theoretical motivations, the possible existence and detection of extra dimensions has been a central point in my work [hepph/0112186,hepth/0309066,hepph/0607112]. More generally, during my research I have been working on possible manifestations of the phenomenology of Quantum Gravity and String Theory, and examined applications for physics at the Planck scale, such as black hole and graviton production [hepph/0109085, hepph/0412265, hepph/0507138]. Even though these effective models are not fundamental, they allow us to make testable predictions for high energy physics and might help us to learn about the general structure of the unknown underlying theory. This is an exciting branch of physics which lives at the intersection of theoretical and experimental physics. Some years ago, I worked out a model which includes the effects of a minimal length scale into quantum field theory [hepth/0305262] possibly with extra dimensions [hepph/0410122], and used it in several applications [hepph/0308138, hepth/0502142, hepph/0405127, hepth/0404232], some of which are still work in progress [0712.2811] . This model is related to Deformed Special Relativity [hepth/0510245, hepth/0702016], but differs in the implementation of the minimal length [hepth/0603032, grqc/0612167]. The Cosmological Problems Cosmology and astrophysics today offer the theoretical physicist many problems to tackle which makes it an attractive research field. The most pressing questions are what is the microscopic origin of dark matter and dark energy. But also the connection to Quantum Gravity is intriguing, addressing the issue of singularity avoidance and vacuum energy. Recently, I have been working on a modification of General Relativity through a bimetric model that introduces a mirrormatter which moves according to the LeviCevita connection of the second metric [0807.2838]. I have not yet closely investigated its potential to address some of the cosmological problems, but I am presently working with some collaborators on structure formation and gravitational lensing. I would like to pursue this further, both to study observational consequences as well as to better understand the theoretical implications.
