Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Whitehead's Principle of Relativity - Unpublished Lectures by J. L.
  Synge, FRS   In Appendix B, there is a proposal about the Limb Effect which could be of
great significance for Solar Physics.
  In his PRINCIPLE OF RELATIVITY, Cambridge University Press, 1922 (republished
Dover, 2004) A. N. Whitehead, making no use of ''curved'' space-time, derived
the same values as Einstein for the red-shift, perihelion advance and the
deflection of light. Synge expounds Whitehead's arguments in modern notation
making it more accessible for contemporary Physicists but also obtains the
Shapiro retardation of electromagnetic radiation by a gravitational field.
Synge compares Einstein's GRT and Whitehead's PR, finding the observational
evidence equally strong for both theories. He alluded to Whitehead's prediction
of a Limb Effect remarking that to pursue its consequences would require a
knowledge of QM which did not exist in 1922. Possibly this was not done because
of physicist's Obsession with GRT since 1919.

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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat