  In ultrarelativistic heavy-ion collisions, enormous magnetic fields are
generated because of fast-moving charged particles. In the presence of these
magnetic fields, the spin of particles is aligned either in the parallel or in
the antiparallel direction with respect to the direction of the magnetic field.
A finite magnetization is thus produced. It is known that a finite magnetic
susceptibility, $\chi_{m}$, changes the evolution of the energy density of the
quark-gluon plasma (QGP), which is believed to be created in these collisions.
Depending on whether the system under consideration is a paramagnetic
($\chi_{m}>0$) or diamagnetic ($\chi_{m}<0$) fluid, it slows down or speeds up
the decay of the energy density, and affects other thermodynamic quantities. In
general, one expects that the magnetic susceptibility depends on the magnetic
field and temperature. Bearing in mind that these parameters evolve with the
evolution of the fluid, a nonuniform magnetic susceptibility in this system is
thus expected. In this work, we first determine $\chi_{m}$ by using a certain
analogy to the standard anisotropic kinetic theory, where the one-particle
distribution function is replaced by the corresponding anisotropic distribution
function. We then determine the proper time dependence of the magnetic
susceptibility in the framework of the ideal transverse magnetohydrodynamics.
We also study the effect of dissipation on the evolution of $\chi_{m}$.
