Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An Isometric Dynamics for a Causal Set Approach to Discrete Quantum
  Gravity   We consider a covariant causal set approach to discrete quantum gravity. We
first review the microscopic picture of this approach. In this picture a
universe grows one element at a time and its geometry is determined by a
sequence of integers called the shell sequence. We next present the macroscopic
picture which is described by a sequential growth process. We introduce a model
in which the dynamics is governed by a quantum transition amplitude. The
amplitude satisfies a stochastic and unitary condition and the resulting
dynamics becomes isometric. We show that the dynamics preserves stochastic
states. By "doubling down" on the dynamics we obtain a unitary group
representation and a natural energy operator. These unitary operators are
employed to define canonical position and momentum operators.

36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat