Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fields of an ultrashort tightly-focused laser pulse   Analytic expressions for the electromagnetic fields of an ultrashort, tightly
focused, linearly polarized laser pulse in vacuum are derived from scalar and
vector potentials, using a small parameter which assumes a small bandwidth of
the laser pulse. The derived fields are compared with those of the Lax series
expansion and the complex-source-point approaches and are shown to be
well-behaved and accurate even in the subcycle pulse regime. We further
demonstrate that terms stemming from the scalar potential and due to a fast
varying pulse envelope are non-negligible and may significantly influence
laser-matter interactions.

28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org