Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measuring Vacuum Polarisation with High Power Lasers   When exposed to intense electromagnetic fields, the quantum vacuum is
expected to exhibit properties of a polarisable medium akin to a weakly
nonlinear dielectric material. Various schemes have been proposed to measure
such vacuum polarisation effects using a combination of high power lasers.
Motivated by several planned experiments, we provide an overview of
experimental signatures that have been suggested to confirm this prediction of
quantum electrodynamics of real photon-photon scattering.

2
The categories of this paper are: math
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
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The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th