Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Glass phenomenology in the hard matrix model   We introduce a new toy model for the study of glasses: the hard-matrix model
(HMM). This may be viewed as a single particle moving on $\mathrm{SO}(N)$,
where there is a potential proportional to the 1-norm of the matrix. The ground
states of the model are "crystals" where all matrix elements have the same
magnitude. These are the Hadamard matrices when $N$ is divisible by four. Just
as finding the latter has challenged mathematicians, our model fails to find
them upon cooling and instead shows all the behaviors that characterize
physical glasses. With simulations we have located the first-order
crystallization temperature, the Kauzmann temperature where the glass would
have the same entropy as the crystal, as well as the standard, measurement-time
dependent glass transition temperature. Our model also brings to light a new
kind of elementary excitation special to the glass phase: the "rubicon". In our
model these are associated with the finite density of matrix elements near
zero, the maximum in their contribution to the energy. Rubicons enable the
system to cross between basins without thermal activation, a possibility not
much discussed in the standard landscape picture. We use these modes to explain
the slow dynamics in our model and speculate about their role in its quantum
extension in the context of many-body localization.

5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th