Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relaxation-time approximation and relativistic third-order viscous
  hydrodynamics from kinetic theory   Using the iterative solution of Boltzmann equation in the relaxation-time
approximation, the derivation of a third-order evolution equation for shear
stress tensor is presented. To this end we first derive the expression for
viscous corrections to the phase-space distribution function, $f(x,p)$, up to
second-order in derivative expansion. The expression for $\delta f(x,p)$
obtained in this method does not lead to violation of the experimentally
observed $1/\sqrt{m_T}$ scaling of the femtoscopic radii, as opposed to the
widely used Grad's 14-moment approximation. Subsequently, we present the
derivation of a third-order viscous evolution equation and demonstrate the
significance of this derivation within one-dimensional scaling expansion. We
show that results obtained using third-order evolution equations are in
excellent accordance with the exact solution of Boltzmann equation as well as
with transport results.

5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
18
The categories of this paper are: econ
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn