Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Protocol-Dependence and State Variables in the Force-Moment Ensemble   Stress-based ensembles incorporating temperature-like variables have been
proposed as a route to an equation of state for granular materials. To test the
efficacy of this approach, we perform experiments on a two-dimensional
photoelastic granular system under three loading conditions: uniaxial
compression, biaxial compression, and simple shear. From the interparticle
forces, we find that the distributions of the normal component of the
coarse-grained force-moment tensor are exponential-tailed, while the deviatoric
component is Gaussian-distributed. This implies that the correct stress-based
statistical mechanics conserves both the force-moment tensor and the
Maxwell-Cremona force-tiling area. As such, two variables of state arise: the
tensorial angoricity ($\hat{\alpha}$) and a new temperature-like quantity
associated with the force-tile area which we name {\it keramicity} ($\kappa$).
Each quantity is observed to be inversely proportional to the global confining
pressure; however only $\kappa$ exhibits the protocol-independence expected of
a state variable, while $\hat{\alpha}$ behaves as a variable of process.

27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
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The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
16
The categories of this paper are: stat