# Serguei NECHAEV

**Birth date**: July 9, 1962
**Place of birth**: Moscow, Russia
**Family status**: Married, 2 children
**Laboratory**: UMR 8626, CNRS-Universite Paris Sud, LPTMS, Bat.100, Universite Paris Sud, 91405 Orsay Cedex, France
**Tel**: 01 69 15 73 32 ; +7 (495) 939 06 63 (Moscow)
**FAX**: 01 69 15 65 25 ;
**e-mail**: nechaev@lptms.u-psud.fr,
sergei.nechaev@gmail.com,
**Education**:
1985: Graduated from the Physical Department of the Moscow State University. Master work in the statistical physics of polymers.
1989: Ph.D. in Physics (Physical Department of the Moscow State University); subject of Ph.D:
"Topological Constraints in the Statistical Physics of Macromolecules".
1996: Doctoral Degree (Dr.Sci.D.) in Physics (Landau Institute for Theoretical Physics); subject of Dr.Sci.D.: "Statistics of Knots and Entangled Random Walks".
**Permanent Employment**:
1985-1991: Stageur, Researcher at the Institute of Chemical Physics (Russian Academy of Sciences).
1991-1998: Researcher, Senior researcher (since 1996) at the Landau Institute for Theoretical Physics (Russian Academy of Sciences).
1998-2008: Charge de Recherche (CR1) at CNRS-Universit Paris Sud, lab. LPTMS
2008-present Directeur de Recherche (DR2) at CNRS-Universit Paris Sud, lab. LPTMS
**Organizational activity**:
2003: Organizer of the trimester at IHP (Institut Henri Poincaré) "Geometry and Statistics of Random Growth"
2004: Organizer of the conference "Geometry and Combinatorics in Physics", (Independent University, Moscow)
2005: Organizer of the conference "Combinatorial Methods in Physics and Knot Theory", (Independent University, Moscow)
2006: Organizer of the conference "Structure formation and random processes on graphs and networks" (LPTMS, Orsay)
2005-2007: Coordinator of the ACI grant ACI-NIM-2004-243 "Nouvelles Interfaces des Mathematiques" (France) "Knots and braids"
**Present scientific interests**:
1. We consider the new class of random matrices - the so-called "randomized Parisi matrices", investigate the spectral properties of these matrices, and discuss their application for description of scale-free networks, as well as for kinetic properties of proteins at low temperatures.
2. For Bernoulli Matching model of sequence alignment problem we apply Bethe ansatz technique via an exact mapping to the 5-vertex model on a square lattice. Considering the terrace-like representation of the sequence alignment problem, we reproduce by the Bethe ansatz the results for the averaged length of the Longest Common Subsequence in Bernoulli approximation. We also compute the average number of nucleation centres of the terraces.
**Recent selected publications (total number of publications: 80)**:
F. Hivert, S. Nechaev, G. Oshanin, O. Vasilyev, On the distribution of surface extrema in several one- and two-dimensional random landscapes, J. Stat. Phys. 126, 243-279 (2007)
M. V. Tamm and S. K. Nechaev, Necklace-cloverleaf transition in associating RNA-like diblock copolymers, Phys. Rev. E 75, 031904 (2007)
S. Majumdar, K. Mallick, S. Nechaev, Bernoulli Matching Model of Random Sequence Alignment: Bethe Ansatz Solution, Phys. Rev. E 77, 011110 (2008)
S.K. Nechaev, M. Tamm, Unzipping of two random heteropolymers: Ground state energy distribution and fnite size effects, Phys. Rev. E, 78, 011903 (2008)
V.A. Avetisov, A.Kh. Bikulov, S.K. Nechaev, Random Hierarchical Matrices: Spectral Properties and Relation to Polymers on Disordered Trees, J. Phys. A 42, 075001 (2009)