Research

In the laboratory a range problems of high-energy physics, general relativity and mathematical physics are investigated. The main topics include:

• Gravitation, cosmology, and string theory
  • Modifications of Einstein's gravity, cosmological models in these theories
  • various cosmological and gravity solutions from string theory compactifications
• High energy physics phenomenology
  • electroweak interaction beyond the Standard Model
  • higher-spin fields and interactions

Current projects

Projects funded by the Estonian Research Council:

• Nonlinear theory of solids and fundamental fields (IUT2-27, 2013-2018)
  Principal investigator: Vladimir Hizhnyakov (Laboratory of Solid State Theory)
  • Subtopic: High Energy Physics and Gravitation
    Senior personnel: Piret Kuusk
    Personnel: Laur Järv, Hannes Liivat, Margus Saal

Projects funded by the Estonian Science Foundation:

• Spin polarization effects in top quark processes and new physics (Grant No. 8769, 2011-2014)
  Principal investigator: Stefan Groote (Laboratory of Field Theory)
  Senior personnel: Hannes Liivat

• Theoretical implications and observational consequences of modified theories of gravity (Grant No. 8837, 2011-2014)
  Principal investigator: Piret Kuusk
  Senior personnel: Laur Järv, Margus Saal
  PhD student: Erik Randla

Some recent publications

• Stefan Groote, Hannes Liivat, Ilmar Ots, Tiit Sepp, Probing scalar particle and unparticle couplings in e+ e- ---> t anti-t with transversely polarized beams, Eur. Phys. J. C66: 271-281 (2010) (preprint version arXiv:0908.2027 [hep-ph])
• Rein Saar, Stefan Groote, Hannes Liivat, Ilmar Ots, Dynamical' interactions and gauge invariance, Phys. Rev. D84: 065022 (2011) (preprint version arXiv:0908.3761 [hep-th])
• L. Järv, P. Kuusk, M. Saal, Potential dominated scalar-tensor cosmologies in the general relativity limit: phase space view, Phys. Rev. D 81, 104007 (2010) (preprint version arXiv:1003.1686 [gr-qc])
• L. Järv, P. Kuusk, M. Saal, Scalar-tensor cosmologies with a potential in the general relativity limit: time evolution, Phys. Lett. B 694, 1 (2010) (preprint version arXiv:1006.1246 [gr-qc])
• Rein Saar, Stefan Groote, Hannes Liivat, Ilmar Ots, Gauge and Lorentz transformation placed on the same foundation, Adv. Math. Phys.  652126 (2011) (preprint version arXiv:1006.2039 [hep-th])
• Stefan Groote, Hannes Liivat, Ilmar Ots, Symmetries and similarities for spin orientation parameters in e^+ e^- -> ZH, Z\gamma, ZZ at SM thresholds, Nucl. Phys. B843  213-222 (2011) (preprint version arXiv:1008.0917 [hep-th])
• L. Järv, P. Kuusk, M. Saal, Scalar-tensor cosmologies with dust matter in the general relativity limit, Phys. Rev. D 85, 064013 (2012) (preprint version arXiv:1112.5308 [gr-qc])