Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Equivalence of time-domain inverse problems and boundary spectral
  problems   We consider inverse problems for wave, heat and Schr\"odinger-type operators
and corresponding spectral problems on domains of ${\bf R}^n$ and compact
manifolds. Also, we study inverse problems where coefficients of partial
differential operator have to be found when one knows how much energy it is
required to force the solution to have given boundary values, i.e., one knows
how much energy is needed to make given measurements. The main result of the
paper is to show that all these problems are shown to be equivalent.

9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int