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Showing 1 to 20 of 26 for “"Instantons"”.
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Analytic aspects of periodic instantons
… of the Riemannian ADHMN construction of instantons on R⁴ is given, preceding a description of the heuristic behind the theory of instantons on quotients of R⁴. The Fredholm theory of twisted Dirac operators on cylindrical manifolds is derived, the spectra of spin Dirac operators on …
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Dynamical signatures of instantons: insights from path-integral studies
… from closed-loop imaginary-time paths called ‘instantons’. This technique has been successfully employed in computing static properties of systems, such as tunneling splittings of energy levels in large molecules. This thesis explores the dynamical imprints of instantons and presents results …
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Infinite-Centre Gibbons-Hawking Metrics, Applied to Gravitational Instantons and Monopoles
… the contexts of four-dimensional gravitational instantons and their applications, Kaluza-Klein monopoles and vortices, gravitational calorons, analytical extensions of Majumdar-Papapetrou metrics to form extreme Reissner-Nordstrom black holes, and Kaluza-Klein black holes. We find that, in most …
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The effects of instantons in a finite temperature quantum field theory
… We show that in this approximation, instantons increase coupling between the quarks. We then show that the dilute gas approximation is suspect in the zero temperature formalism because divergences occur when trying to include instantons of all sizes in the theory. We then introduce …
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The semi-classical approximation in a hierarchy of models with instantons
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-20T16:52:56Z No. of bitstreams: 1 1980_neinast.pdf: 2304128 bytes, checksum: 5411988c7855ca58a2b3ebd5e4f54dca (MD5)
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Fluctuations and Instantons in Complex Landscapes: From Ligand Unbinding to Proton Transfer
Biophysical entities are complex systems systems with strong environmental coupling, dominated by fluctuations on a hierarchy of timescales. These properties confound simulation of ligand binding and catalysis, inflating the scale of the problem to one tractable only with a considerable outlay of …
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Some non-perturbative results in relativistic field theory
… interesting because 't Hooft monopoles appear as instantons in the Georgi-Glashow theory of weak and electromagnetic interactions. The interactions of the instantons are directly related to the question of confinement of the fermions in this theory.
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Confinement and Chiral Phase Transitions in SU(2) Gauge Theory via Topological Objects
… the constituents of the finite-temperature instantons with non-trivial holonomy. I present a comprehensive numerical study of the confining properties in SU(2) Yang-Mills theory at finite temperature, obtaining important observables which are then compared with available data from state of …
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Semiclassical Methods in Field Theories: The Use of Soliton and Instanton
… type problem. We study the interaction among instantons, examine the dilute gas limit assumption, and compute the vacuum state wave functionals and eigen-energies. We also study the method to generate envelope solutions out of a family of existing instanton solutions.
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Some analytic aspects of Vafa-Witten twisted N̳ = 4 supersymmetric Yang-Millseory theory
… moduli spacesMASD of compactified anti-self-dual instantons. For several algebraic surfaces, these Euler characteristics were verified to be modular forms. Except in certain special cases, it's unclear how to precisely define the partition function. If there is a mathematically sensible definition …
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Geometry of SU(3) Manifolds
… or more generally, $\omega$-anti-self dual instantons; The third is pseudo-holomorphic curves.</p><p>For the first perspective, I am interested in the interplay between $SU(3)$ structures and their special Lagrangian submanifolds. More precisely, I study $SU(3)$-structures which locally …
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The wave function of the universe
… show that even the class of bulk matter wormhole instantons found by Carlini and Mijic (1990) are predicted in the quantum theory. However, unresolved issues and newfound problems seem to threaten the wormhole theory. Furthermore, since there are no a priori notions of time (and space) present in …
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Physics-inspired Computing and its Applications
… zero-amplitude holes, which are known as instantons in one dimension, or rarefaction pulses in two dimensions. It is found that these transient zero-amplitude holes allow the system to remove initially present global phase wind- ings which are topologically protected, thereby allowing the …
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Geometric aspects of three dimensional N = 4 gauge theories
… Higgs branch coincides with a moduli space of instantons. We compute hemisphere blocks for the theory and explicitly recover Verma module characters of the Coulomb branch chiral ring. In this example, the blocks have interesting combinatorial content and can be related to generating functions …
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BPS Approaches to Anyons, Quantum Hall States and Quantum Gravity
… suggest the inclusion of certain gravitational instantons in the path integral. An explicit computation in a minimally supersymmetric case illustrates the principles at work, and highlights the role of a hitherto unidentified scale in quantum gravity. It also is an interesting result in itself: …
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Self-duality for SU([infinity]) gauge theories and extended objects
… We also show that the self-intersecting string instantons, introduced by Polyakov constitute a special case of these solutions. Of particular interest are two octonionic classes: a membrane in 7 dimensions and a 3-brane in 8 dimensions. To simplify the calculations in these cases we developed an …
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Pattern-forming in non-equilibrium quantum systems and geometrical models of matter
… families of manifolds, namely ALF gravitational instantons of types A_k and D_k, are investigated as possible models for multi-particle systems. On the basis of their topological and geometrical properties it is concluded that A_k can model a system of k+1 electrons, and D_k a system of a proton …
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The geometry and representation theory of superconformal quantum mechanics
… The low-energy dynamics of Yang-Mills instantons is an example of the latter and arises naturally in the discrete light-cone quantisation (DLCQ) of certain superconformal field theories. In particular, we study in some detail the quantum mechanics arising in the DLCQ of the …
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Ring-polymer approaches to instanton theory
… practical method for locating multidimensional instantons is proposed, by computing saddle points on the ring-polymer surface, and a derivation for the reaction rate constant based on the "ImF" premise using the ring-polymer formalism is shown to be far simpler than in previous instanton …
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The instanton liquid and the axion
… of the cosmology of axions. Axions couple to QCD instantons and these non-perturbative effects are modeled within the framework of the interacting instanton liquid model (IILM). The thesis describes the significant advances made within the IILM in order to study the quark-gluon plasma in realistic …
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