Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Breakdown of Lorentz Invariance for Spin-1/2 Particle Motion in Curved
  Space-Time with Applications to Muon Decay   This paper explores the properties of the Pauli-Lubanski spin vector for the
general motion of spin-1/2 particles in curved space-time. Building upon
previously determined results in flat space-time, it is shown that the
associated Casimir scalar for spin possesses both gravitational contributions
and frame-dependent contributions due to non-inertial motion, where the latter
represents a possible quantum violation of Lorentz invariance that becomes
significant at the Compton wavelength scale. When applied to muon decay near
the event horizon of a microscopic Kerr black hole, it is shown that its
differential cross section is strongly affected by curvature, with particular
sensitivity to changes in the black hole's spin angular momentum. In the
absence of curvature, the non-inertial contributions to the decay spectrum are
also identified and explored in detail, where its potential for observation is
highest for large electron opening angles. It is further shown how possible
contributions to noncommutative geometry can emerge from within this formalism
at some undetermined length scale. Surprisingly, while the potential exists to
identify noncommutative effects in muon decay, the relevant terms make no
contribution to the decay spectrum, for reasons which remain unknown.

24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th