Alexander Arkadyevich Migdal (Russian: Александр Арка́дьевич Мигдал; born 22 July 1945) is a Russian-American mathematical and theoretical physicist currently working at the Institute for Advanced Study in Princeton, New Jersey.

Following defection, Migdal spent the 1988 academic year at UC San Diego, before accepting a tenured professorship at Princeton University, with joint appointments to the departments of physics and applied mathematics.

This work ran counter to prevailing orthodoxy within the Soviet physics establishment, causing their paper, Spontaneous Breakdown of Strong Interaction Symmetry and Absence of Massless Particles,[2] to be rejected by JETP in 1964 and 1965, before finally being accepted for publication in mid-1966.

Migdal's work from 1974 to 1980 was focused on quantum chromodynamics, starting with a paper from 1975 in which he was first to establish how asymptotic freedom could lead to quark confinement by employing a novel form of the renormalization group.

[10] This work was popularized by Ken Wilson and Leo Kadanoff[11] and later became known as the “Migdal-Kadanoff bond-moving approximation,”[12] with lasting application in solid-state physics.

In 1979, Migdal developed an exact relationship between quark confinement and asymptotic freedom in the form of a nonperturbative equation for the Wilson loop, in collaboration with his student, Yuri Makeenko.

In collaboration with David Gross, Migdal further developed this work in a widely cited paper from 1990,[16] providing the first exact solution for 2D quantum gravity.