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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Multiparameter quantum groups : contractions and coloured generalisations

Parashar, Deepak January 2000 (has links)
No description available.
2

Deformations of Conformal Field Theories to Models with Noncommutative

Harald Grosse, Karl-Georg Schlesinger, grosse@doppler.thp.univie.ac.at 01 September 2000 (has links)
No description available.
3

Actions of Finite Groups on Substitution Tilings and Their Associated C*-algebras

Starling, Charles B 01 February 2012 (has links)
The goal of this thesis is to examine the actions of finite symmetry groups on aperiodic tilings. To an aperiodic tiling with finite local complexity arising from a primitive substitution rule one can associate a metric space, transformation groupoids, and C*-algebras. Finite symmetry groups of the tiling act on each of these objects and we investigate appropriate constructions on each, namely the orbit space, semidirect product groupoids, and crossed product C*-algebras respectively. Of particular interest are the crossed product C*-algebras; we derive important structure results about them and compute their K-theory.
4

Actions of Finite Groups on Substitution Tilings and Their Associated C*-algebras

Starling, Charles B 01 February 2012 (has links)
The goal of this thesis is to examine the actions of finite symmetry groups on aperiodic tilings. To an aperiodic tiling with finite local complexity arising from a primitive substitution rule one can associate a metric space, transformation groupoids, and C*-algebras. Finite symmetry groups of the tiling act on each of these objects and we investigate appropriate constructions on each, namely the orbit space, semidirect product groupoids, and crossed product C*-algebras respectively. Of particular interest are the crossed product C*-algebras; we derive important structure results about them and compute their K-theory.
5

Actions of Finite Groups on Substitution Tilings and Their Associated C*-algebras

Starling, Charles B 01 February 2012 (has links)
The goal of this thesis is to examine the actions of finite symmetry groups on aperiodic tilings. To an aperiodic tiling with finite local complexity arising from a primitive substitution rule one can associate a metric space, transformation groupoids, and C*-algebras. Finite symmetry groups of the tiling act on each of these objects and we investigate appropriate constructions on each, namely the orbit space, semidirect product groupoids, and crossed product C*-algebras respectively. Of particular interest are the crossed product C*-algebras; we derive important structure results about them and compute their K-theory.
6

Chern Character for Global Matrix Factorizations

Platt, David 03 October 2013 (has links)
We give a formula for the Chern character on the DG category of global matrix factorizations on a smooth scheme $X$ with superpotential $w\in \Gamma(\O_X)$. Our formula takes values in a Cech model for Hochschild homology. Our methods may also be adapted to get an explicit formula for the Chern character for perfect complexes of sheaves on $X$ taking values in right derived global sections of the De-Rham algebra. Along the way we prove that the DG version of the Chern Character coincides with the classical one for perfect complexes.
7

Actions of Finite Groups on Substitution Tilings and Their Associated C*-algebras

Starling, Charles B January 2012 (has links)
The goal of this thesis is to examine the actions of finite symmetry groups on aperiodic tilings. To an aperiodic tiling with finite local complexity arising from a primitive substitution rule one can associate a metric space, transformation groupoids, and C*-algebras. Finite symmetry groups of the tiling act on each of these objects and we investigate appropriate constructions on each, namely the orbit space, semidirect product groupoids, and crossed product C*-algebras respectively. Of particular interest are the crossed product C*-algebras; we derive important structure results about them and compute their K-theory.
8

Constraining New Physics with Colliders and Neutrinos

Sun, Chen 06 June 2017 (has links)
In this work, we examine how neutrino and collider experiments can each and together put constraints on new physics more stringently than ever. Constraints arise in three ways. First, possible new theoretical frameworks are reviewed and analyzed for the compatibility with collider experiments. We study alternate theories such as the superconnection formalism and non-commutative geometry (NCG) and show how these can be put to test, if any collider excess were to show up. In this case, we use the previous diboson and diphoton statistical excess as examples to do the analysis. Second, we parametrize low energy new physics in the neutrino sector in terms of non-standard interactions (NSI), which are constrained by past and proposed future neutrino experiments. As an example, we show the capability of resolving such NSI with the OscSNS, a detector proposed for Oak Ridge National Lab and derive interesting new constraints on NSI at very low energy (≲ 50 MeV). Apart from this, in order to better understand the NSI matter effect in long baseline experiments such as the future DUNE experiment, we derive a new compact formula to describe the effect analytically, which provides a clear physical picture of our understanding of the NSI matter effect compared to numerical computations. Last, we discuss the possibility of combining neutrino and collider data to get a better understanding of where the new physics is hidden. In particular, we study a model that produces sizable NSI to show how they can be constrained by past collider data, which covers a distinct region of the model parameter space from the DUNE experiment. In combining the two, we show that neutrino experiments are complementary to collider searches in ruling out models such as the ones that utilize a light mediator particle. More general procedures in constructing such models relevant to neutrino experiments are also described. / Ph. D. / As we know, all matter in our daily life is made of particles called atoms and molecules, which are in turn formed by subatomic particles: protons, neutrons, and electrons. If one further divides the former two with certain technology, such as using a proton collider to smash one into another, it goes to the regime of elementary particles. It is shown experimentally that all matter we know is made of elementary particles that cannot be further divided. They include quarks and leptons. Together with the force carrier particles (also called gauge bosons) and the Higgs scalar, they form the Standard Model of particle physics. In this work, we study the properties of elementary particles and the way they interact with each other that are different from the Standard Model predictions. We conduct the research study in the following two aspects: collider phenomena and neutrino phenomena. These two aspects cover the high energy regime of particle scattering process and low energy regime of neutrino propagation, which are two important sectors of great interest recently. As a result of the analysis, we discuss possible ways that the new physics is hidden yet can be detected with next generation experiments.
9

On the JLO Character and Loop Quantum Gravity

Lai, Chung Lun Alan 31 August 2011 (has links)
In type II noncommutative geometry, the geometry on a C∗-algebra A is given by an unbounded Breuer–Fredholm module (ρ,N,D) over A. Here ρ:A→N is a ∗-homomorphism from A to the semi-finite von Neumann algebra N⊂B(H), and D is an unbounded Breuer–Fredholm operator affiliated with N that satisfies certain axioms. Each Breuer–Fredholm module assigns an index to a given element in the K-theory of A. The Breuer–Fredholm index provides a real-valued pairing between the K-homology and the K-theory of A. When N=B(H), a construction of Jaffe-Lesniewski-Osterwalder associates to the module (ρ,N,D) a cocycle in the entire cyclic cohomology group of A for D is theta-summable. The JLO character and the K-theory character intertwine the K-theoretical pairing with the pairing of entire cyclic theory. If (ρ,N,F) is a finitely summable bounded Breuer–Fredholm module, Benameur-Fack defined a cocycle generalizing the Connes's cocycle for bounded Fredholm modules. On the other hand, given a finitely-summable unbounded Breuer–Fredholm module, there is a canonically associated bounded Breuer–Fredholm module. The first main result of this thesis extends the JLO theory to Breuer–Fredholm modules (possibly N does not equal B(H)) in the graded case, and proves that the JLO cocycle and Connes cocycle define the same class in the entire cyclic cohomology of A. This extends a result of Connes-Moscovici for Fredholm modules. An example of an unbounded Breuer–Fredholm module is given by the noncommutative space of G-connections due to Aastrup-Grimstrup-Nest. In their original work, the authors limit their construction to the case that the group G=U(1) or G=SU(2). Another main result of the thesis extends AGN’s construction to any connected compact Lie group G; and generalizes by considering connections defined on sequences of graphs, using limits of spectral triples. Our construction makes it possible to equip the module (ρ,N,D) with a Z_2-grading. The last part of this thesis studies the JLO character of the Breuer–Fredholm module of AGN. The definition of this Breuer–Fredholm module depends on a divergent sequence. A concrete condition on possible perturbations of the sequence ensuring that the resulting JLO class remains invariant is established. The condition implies a certain functoriality of AGN’s construction.
10

On the JLO Character and Loop Quantum Gravity

Lai, Chung Lun Alan 31 August 2011 (has links)
In type II noncommutative geometry, the geometry on a C∗-algebra A is given by an unbounded Breuer–Fredholm module (ρ,N,D) over A. Here ρ:A→N is a ∗-homomorphism from A to the semi-finite von Neumann algebra N⊂B(H), and D is an unbounded Breuer–Fredholm operator affiliated with N that satisfies certain axioms. Each Breuer–Fredholm module assigns an index to a given element in the K-theory of A. The Breuer–Fredholm index provides a real-valued pairing between the K-homology and the K-theory of A. When N=B(H), a construction of Jaffe-Lesniewski-Osterwalder associates to the module (ρ,N,D) a cocycle in the entire cyclic cohomology group of A for D is theta-summable. The JLO character and the K-theory character intertwine the K-theoretical pairing with the pairing of entire cyclic theory. If (ρ,N,F) is a finitely summable bounded Breuer–Fredholm module, Benameur-Fack defined a cocycle generalizing the Connes's cocycle for bounded Fredholm modules. On the other hand, given a finitely-summable unbounded Breuer–Fredholm module, there is a canonically associated bounded Breuer–Fredholm module. The first main result of this thesis extends the JLO theory to Breuer–Fredholm modules (possibly N does not equal B(H)) in the graded case, and proves that the JLO cocycle and Connes cocycle define the same class in the entire cyclic cohomology of A. This extends a result of Connes-Moscovici for Fredholm modules. An example of an unbounded Breuer–Fredholm module is given by the noncommutative space of G-connections due to Aastrup-Grimstrup-Nest. In their original work, the authors limit their construction to the case that the group G=U(1) or G=SU(2). Another main result of the thesis extends AGN’s construction to any connected compact Lie group G; and generalizes by considering connections defined on sequences of graphs, using limits of spectral triples. Our construction makes it possible to equip the module (ρ,N,D) with a Z_2-grading. The last part of this thesis studies the JLO character of the Breuer–Fredholm module of AGN. The definition of this Breuer–Fredholm module depends on a divergent sequence. A concrete condition on possible perturbations of the sequence ensuring that the resulting JLO class remains invariant is established. The condition implies a certain functoriality of AGN’s construction.

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