Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydrodynamics, density fluctuations and universality in conserved
  stochastic sandpiles   We study conserved stochastic sandpiles (CSSs), which exhibit an
active-absorbing phase transition upon tuning density $\rho$. We demonstrate
that a broad class of CSSs possesses a remarkable hydrodynamic structure: There
is an Einstein relation $\sigma^2(\rho) = \chi(\rho)/D(\rho)$, which connects
bulk-diffusion coefficient $D(\rho)$, conductivity $\chi(\rho)$ and
mass-fluctuation, or scaled variance of subsystem mass, $\sigma^2(\rho)$.
Consequently, density large-deviations are governed by an equilibriumlike
chemical potential $\mu(\rho) \sim \ln a(\rho)$ where $a(\rho)$ is the activity
in the system. Using the above hydrodynamics, we derive two scaling relations:
As $\Delta = (\rho - \rho_c) \rightarrow 0^+$, $\rho_c$ being the critical
density, (i) the mass-fluctuation $\sigma^2(\rho) \sim \Delta^{1-\delta}$ with
$\delta=0$ and (ii) the dynamical exponent $z = 2 + (\beta -1)/\nu_{\perp}$,
expressed in terms of two static exponents $\beta$ and $\nu_{\perp}$ for
activity $a(\rho) \sim \Delta^{\beta}$ and correlation length $\xi \sim
\Delta^{-\nu_{\perp}}$, respectively. Our results imply that conserved Manna
sandpile, a well studied variant of the CSS, belongs to a distinct universality
- {\it not} that of directed percolation (DP), which, without any conservation
law as such, does not obey scaling relation (ii).

22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex