Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Models for Chronology Selection   In this paper, we derive an expression for the grand canonical partition
function for a fluid of hot, rotating massless scalar field particles in the
Einstein universe. We consider the number of states with a given energy as one
increases the angular momentum so that the fluid rotates with an increasing
angular velocity. We find that at the critical value when the velocity of the
particles furthest from the origin reaches the speed of light, the number of
states tends to zero. We illustrate how one can also interpret this partition
function as the effective action for a boosted scalar field configuration in
the product of three dimensional de Sitter space and $S^1$. In this case, we
consider the number of states with a fixed linear momentum around the $S^1$ as
the particles are given more and more boost momentum. At the critical point
when the spacetime is about to develop closed timelike curves, the number of
states again tends to zero. Thus it seems that quantum mechanics naturally
enforces the chronology protection conjecture by superselecting the causality
violating field configurations from the quantum mechanical phase space.

9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
2
The categories of this paper are: math