Pure & Applied MathematicsPure & Applied Mathematicshttp://hdl.handle.net/2262/592017-03-29T11:13:30Z2017-03-29T11:13:30ZSpike train analysisCooney, Cathalhttp://hdl.handle.net/2262/795332017-02-24T03:21:51Z2015-01-01T00:00:00ZSpike train analysis
Cooney, Cathal
This thesis focuses on the study of spike trains, the information carrying signals conveyed by neurons in the nervous system. Spiking data from songbirds from [Narayan et al., 2006] was used prominently in this thesis. Multi-unit data for Chapter Three was simulated using a model network from [Houghton and Sen, 2008].
2015-01-01T00:00:00ZA dynamical study of the chirally rotated Schrödinger functional in lattice QCDBrida, Mattia Dallahttp://hdl.handle.net/2262/794952017-02-24T03:11:35Z2015-01-01T00:00:00ZA dynamical study of the chirally rotated Schrödinger functional in lattice QCD
Brida, Mattia Dalla
In this work, we present first results from dynamical simulations of the chirally rotated Schrödinger functional (SF) in lattice QCD. More specifically, we discuss the determination of renormalization constants of quark-bilinears, and show evidence for the expected automatic 0(α) improvement of these determinations. After a short introduction on the topics of non-perturbative renormalization and improvement in lattice field theory, we recall the technical advantages of renormalization schemes based on the SF. We then motivate and discuss the lattice regularization of the SF with chirally rotated boundary conditions, and present details and tests on the simulation algorithm. Finally, we comment on the results and on future possible applications of the method.
2015-01-01T00:00:00ZIntegrable lattice models for strongly correlated electronsQuinn, Eoinhttp://hdl.handle.net/2262/793172017-02-10T11:24:49Z2013-01-01T00:00:00ZIntegrable lattice models for strongly correlated electrons
Quinn, Eoin
This thesis is dedicated to the study of a new family of integrable lattice models for strongly correlated electrons, namely the Hubbard- Shastry models. The techniques of exactly solvable models, and in particular those of integrable systems, are used. The models are constructed through the quantum inverse scattering method and are studied in one dimension through their Bethe ansatz solution.
2013-01-01T00:00:00ZSpectroscopy and scattering of mesons containing charm quarks from lattice QCDMoir, Grahamhttp://hdl.handle.net/2262/792522017-02-10T11:06:56Z2013-01-01T00:00:00ZSpectroscopy and scattering of mesons containing charm quarks from lattice QCD
Moir, Graham
We present excited spectra of mesons containing charm-light (D), charm-strange (Ds) and charm-charm (charmoninm) combinations. We perform these spectroscopic calculations on two volumes. 16(3) X 128 and 24(3) x 128, of dynamical Nf = 2 + 1 configurations generated by the Hadron Spectrum Collaboration. These ensembles have unphysically-heavy degenerate up and down quarks, resulting in a pion mass of ~ 391 MeV. Our use of distillation and the variational method combined with a large basis of carefully constructed interpolators allows us to extract and reliably identify the continuum spin of an extensive set of states up to J ≤ 4, while also allowing access to explicit gluonic degrees of freedom. For the first time in a lattice QCD calculation, we extract charmoninm states with exotic quantum nmnbers 0+-, 1-+ and 2+-, and in all three sectors, we identify the lightest hybrid supermultiplet and evidence for an excited hybrid supermultiplet. Using a non-relativistic interpretation of some of our interpolators in the open-charm sectors, we calculate mixing angles for P-wave, D-wave and the hybrid 1-, spin-singlet triplet states. We also present preliminary results for the isospin. I = 3/2. Dπ multi-particle spectrum and map out. via the Lüscher formalism, the l = 0 elastic scattering phase shift. As expected we do not find a resonance in this channel.
2013-01-01T00:00:00Z