Scientific interests.

Main scientific interests are with atomic and molecular physics and low-energy tests of the standard model. That includes:

• Development of new methods in atomic and molecular theory. An accurate and reliable atomic theory should account for the electron correlations, relativistic and QED effects. Modern methods usually provide accurate results only for particular “simple” cases, such as light atoms, alkalis or ions with few electrons. More general methods can be developed, for example, by including QED corrections and core-valence correlation effects by properly defined effective operators for valence electrons of an atom or a molecule. After that, conventional methods can be used to solve the few-electron problem for valence electrons.
• Parity nonconservation (PNC) in atoms and molecules. Precision calculations of PNC amplitudes in heavy atoms in order to test standard model at the level of radiation corrections. Search for the possibilities to measure nuclear spin-dependent PNC effects, which will test weak interaction theory in hadronic sector. Search for new PNC phenomena in atomic physics.
• PNC and time-reversal violation and permanent electric dipole moments (EDMs) of atoms and molecules. Standard model predicts exceptionally small EDMs of atoms and molecules, while most other theories predict EDMs, which are orders of magnitude larger. That allows to test the physics beyond the standard model in a table-scale experiments. Therefore, a search for the systems, where EDM is enhanced is very important. When such a system is found, reliable calculation of the EDM enhancement is essential.
• Space-time variation of fundamental constants. We know very little about the nature of the fundamental constants, such as the fine structure constant. Modern theory can not predict their values, which are taken from the experiment. On the other hand, renormalization technique which is used to substitute bare constants with dressed ones depends on the vacuum condensates, gravitational potential, etc. Therefore, it is quite natural to assume that observed dressed constants may change on the cosmological time-scale. Experimental observation of such changes would be of great importance for fundamental theory. Atomic and molecular spectroscopy can be used as a most sensitive tool to study time-variation of the fine structure constant and of the m_p to m_e ratio.
• Time-reversal violation without parity nonconservation, or T-odd, P-even (TOPE) effects. In modern theory it is usually assumed that time-reversal violation is always accompanied with parity nonconservation. However, direct experimental limits on TOPE interactions are rather weak, mainly because of the lack of the convenient observable (such as EDM). If such an observable is found, it can be possible to increase experimental sensitivity by several orders of magnitude.
• Quantum chaos. In order to test fundamental symmetries in atomic physics, one is looking for a system, where small perturbations are enhanced. When such an enhancement is of a general nature (i.e. takes place for the whole region of a spectrum, rather than for some particular levels), the system becomes chaotic. That means that conventional theoretical approaches do not work and new methods are necessary.