[research interests] [CV] [publications] [applied math student seminar] [Contact info] [Teaching]

Nir Gavish

PhD student
School of Mathematical Sciences
Tel Aviv University

I'm a Ph.D. student in Prof. Gadi Fibich's group in the School of Mathematical sciences at the Tel Aviv University.

Research interests:

My research interests lie in applied mathematics. In particular, using a combination of tools such as mathematical modeling, asymptotic analysis, numerical methods, rigorous analysis, and collaboration with experimentalists in order to solve problems that arise from exciting applications.

 

Here is my detailed research statement.

 

My main research topic is the theory of singular solutions of the nonlinear Schrödinger equation (NLS) in the context of nonlinear Optics. In nonlinear Optics, the NLS models the propagation of intense laser beams in a medium such as air, water or glass. Such intense laser beams undergo catastrophic self-focusing up to a point of collapse where, mathematically, the solution becomes singular.  One of the open questions in this field for more than 40 years is what is the behavior of NLS solutions as they collapse.   Since the 80s, the common perception is that all singular solutions of the NLS collapse with a single profile known as the Townes profile. 

 

In my research I show that this common perception is false, by showing that there are also NLS solutions that do not collapse with the Townes profile, but rather collapse with a ring profile. Our prediction was later confirmed experimentally by the nonlinear Optics laboratory in Cornell University, in collaboration with us.  Our research also included a comprehensive numerical study of NLS solutions as they approach singularity for which we developed a novel numerical method for solving such singular problems.

 

Recently I have also branched out of those fields into auction theory.

Scientific publications:

 

Singular standing-ring solutions of nonlinear partial differential equations

Submitted to Physica D, 2009

 

  • A. Ditkowsky and N. Gavish

A grid redistribution method for singular problems

Journal of Computational physics 228: 2354-2365, 2009

 

  • N. Gavish, G. Fibich, L. T. Vuong and  A. L. Gaeta 

      Predicting the filamentation of high-power beams and pulses without numerical integration: A nonlinear Geometrical Optics method
      Physical Review A 78: 043807, 2008

 

  • G. Fibich and N. Gavish

Critical power of collapsing vortices

Phys. Rev. A 77: 045803, 2008

 

  • G. Fibich and N. Gavish

Theory of singular vortex solutions of the nonlinear Schrodinger equation

      Physica D 237: 2696-2730, 2008

  • G. Fibich, N. Gavish, and  X.P. Wang

Singular ring solutions of critical and supercritical nonlinear Schrodinger equations
Physica
231: 55-86, 2007

paper has been selected as one of the winners of the 2007 SIAM Student Paper Competition

 

  • A. Ditkowski, G. Fibich and N. Gavish

Efficient solution of Ax(k) = b(k) using A-1
Journal of Scientific Computing  32: 29-44, 2007

 

  • T. D. Grow, A. A. Ishaaya, L. T. Vuong, A. L. Gaeta, N. Gavish, and G. Fibich

Collapse dynamics of super-Gaussian Beams
Optics Express 14: 5468-5475,  2006

 

  • G. Fibich,  N. Gavish and  X.P. Wang

New singular solutions of the nonlinear Schrodinger equation
Physica D 211: 193-220, 2005

Applied Math student seminar

Together with Guy Baruch, we organize the Applied Math student seminar here at TAU.

CV

Here are my CV and list of publications

 

Contact info

My work email is nirgvsh@ tau.ac.il.
Tel. 972-3-6406210

Lab:

Room 025, ground floor, Schreiber building.

Internal POB:

First floor, Schreiber building.

Mailing address:

Nir Gavish
School of Mathematical Sciences
Tel Aviv University
Tel Aviv 69978
Israel

Teaching

Numerical Analysis for Engineers, Semester A, 2008