Quantum field theories arise as low energy effective descriptions for
states of quantum many-body systems.
Although strongly coupled quantum field theories are common in condensed
systems, currently there is no systematic way of understanding those
Sometimes, strongly coupled field theories have weak coupling description in terms of degrees of freedom which are not point-like particles anymore,
as is the case in the correspondence between gauge theory and string theory. In this talk, I will discuss about 2+1 dimensional non-Fermi liquid states whose low energy effective theory is likely to be a matrix/string theory.