Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can a single gradientless light beam drag particles?   Usually a light beam pushes a particle when the photons act upon it. This is
due to that the electric-dipole particle in the paraxial beam is considered. We
investigate the scattering forces in non-paraxial gradientless beams and find
that the forces can drag certain particles towards the beam source. The major
criterion to be carried out to get the attractive force is the strong
non-paraxiality of the light beam. The cone angle denoting the non-paraxiality
has been investigated to unveil its importance on achieving dragging force. We
hope the attractive forces will be very useful in nanoparticle manipulation.

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The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: cond-mat
6
The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org