In the Dark

The other day I mentioned the forthcoming graduation of a Maynooth PhD student. His name is Aonghus Hunter-McCabe and his main supervisor was Maynooth colleague Brian Dolan, and I just took over when Brian retired to see Aognhus through the latter stages. Anyway, asof yesterday, his thesis is available on arXiv (on hep-th) as well as on the Maynooth University Research Archive Library (MURA) here, so as it is all in the public domain I thought I would advertise it here, as I think it is very good indeed (though I would say that!) and also in case anyone out there is looking to employ a PDRA in a related area…

The abstract is:

This thesis explores the application of differential geometric and general relativistic techniques to deepen our understanding of quantum mechanical systems. We focus on three systems, employing these mathematical frameworks to uncover subtle features within each. First, we examine Unruh radiation in the context of an accelerated two-state atom, determining transition frequencies for a variety of accelerated trajectories via first-order perturbation theory. For harmonic motion of the atom in a vacuum, we derive transition rates with potential experimental realizations. Next, we investigate the quantum Hall effect in a spherical geometry using the Dirac operator for non-interacting fermions in a background magnetic field generated by a Wu-Yang monopole. The Atiyah-Singer index theorem constrains the degeneracy of the ground state, and the fractional quantum Hall effect is studied using the composite fermion model, where Dirac strings associated with the monopole field supply the statistical gauge field vortices. A unique, gapped ground state emerges, yielding fractions of the form ν=1/(2⁢k+1) for large particle numbers. Finally, we examine the AdS/CMT correspondence through a bulk fermionic field in an RN-AdS₄ background (with a U(1) gauge field), dual to a boundary fermionic operator. Spherical and planar event horizon geometries are discussed, with the temperature of the RN black hole identified with that of the dual system on the boundary. By numerically solving for the spectral functions of the dual theory, for a spherical event horizon at zero temperature, we identify a shift in the Fermi surface from that which arises in the planar case. Preliminary evidence of a phase transition emerges upon examining these spectral functions, again for the spherical horizon, at non-zero temperature.

arXiv:2502.13009