Ilya Lifshitz was born into a
Ukrainian Jewish family in Kharkov,
Kharkov Governorate,
Russian Empire (now
Kharkiv,
Ukraine). Together with
Arnold Kosevich, in 1954 Lifshitz established the connection between the oscillation of magnetic characteristics of metals and the form of an electronic surface of Fermi (Lifshitz–Kosevich formula) from
de Haas–van Alphen experiments. Lifshitz was one of the founders of the theory of disordered systems. He introduced some of the basic notions, such as
self-averaging, and discovered what is now called
Lifshitz tails and
Lifshitz singularity. In
perturbation theory, Lifshitz introduced the notion of
spectral shift function, which was later developed by
Mark Krein. A
phase transition involving topological changes of the material's
Fermi surface is called a
Lifshitz phase transition. Starting from the late 1960s, Lifshitz started considering problems of statistical physics of polymers. Together with his students Alexander Grosberg and Alexei R. Khokhlov, Lifshitz proposed a theory of coil-to-globule transition in homopolymers and derived the formula for the conformational entropy of a polymer chain, that is referred to as the Lifshitz entropy. ==References==