Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Equivalence of the Fermat potential and the lensing potential approaches
  to computing the integrated Sachs-Wolfe effect   We show in detail that the recently derived expression for evaluating the
integrated Sachs-Wolfe (ISW) temperature shift in the cosmic microwave
background (CMB) caused by individual embedded (compensated) lenses is
equivalent to the conventional approach for flat background cosmologies. The
conventional approach requires evaluating an integral of the time derivative of
the lensing potential, whereas the new Fermat potential approach is simpler and
only requires taking a derivative of the potential part of the time delay.

31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs