  Understanding non-Fermi liquids in dimensions higher than one remains one of
the most formidable challenges in modern condensed matter physics. These
systems, characterized by an abundance of gapless degrees of freedom and the
absence of well-defined quasiparticles, defy conventional analytical
frameworks. Inspired by recent work on the bosonization of Fermi surfaces
[Delacretaz, Du, Mehta, and Son, Physical Review Research, 4, 033131 (2022)],
we present a procedure for bosonizing non-Fermi liquids, which provides a
holistic approach capable of addressing their intricate physics. Our method
involves parameterizing the generalized fermionic distribution function through
a bosonic field that describes frequency-dependent local variations of the
chemical potential in momentum space. We propose an effective action that
produces the collisionless quantum Boltzmann equation as its equation of motion
and can straightforwardly be used for any dimension and Fermi surface of
interest. Even at the quadratic order, this action reproduces highly
non-trivial results obtainable only through involved analysis with alternative
means. By offering a comprehensive description of the physics of non-Fermi
liquids, our work stands as an important building block in advancing the
comprehension of strange metals and associated phenomena.
