Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The geometry of spacetime with superluminal phenomena   Recent theoretical results show the existence of arbitrary speeds (0 <= v <
\infty) solutions of all relativistic wave equations. Some recent experiments
confirm the results for sound waves. The question arises naturally: What is the
appropriate geometry of spacetime to describe superluminal phenomena? In this
paper we present a spacetime model that incorporates the valid results of
Relativity Theory and yet describes coherently superluminal phenomena without
paradoxes.

31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an