Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Elliptic flow analysis with non-hydro mode in viscous hydrodynamics   Hydrodynamics has been quite suitably used to model the thermal stage of the
heavy-ion collision experiments especially in the low transverse momentum
regime. But the satisfactory agreement of hydrodynamics for proton-proton
collision has stirred up the discussions about the smallest volume for which
the hydrodynamics can be applied. The meaning of hydrodynamics itself has been
under scrutiny with non-requirement of local thermal equilibrium for its
applicability. The second order viscous hydrodynamics requires a transport
coefficient called relaxation time, which had to be included to avoid the
causality violation in the system. This relaxation time controls the non-hydro
mode in an out of equilibrium hydrodynamics theory. In phenomenological studies
this relaxation time has been taken as a constant and much attention has gone
into fixing shear viscosity to entropy density ratio, $\eta/s$. The dynamics of
hydro and non-hydro modes govern the evolution of the system. In the present
work, we study the effect of the variation of the relaxation times on the
elliptic flow in Pb-Pb system, at $\sqrt{s_{NN}}=$2.76 TeV center-of-mass
energy with optical Glauber and IPGlasma initial conditions. We find that this
system operates throughout within the hydrodynamic regime. Non-hydro mode
structure of the theory does not affect flow in the most central collisions and
there is a noticeable increase in flow due to the initial state fluctuations.

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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th