Klee Irwin

Mr. Klee Irwin

Quantum Gravity Research
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
17 March 2017 in Classical and Quantum Gravity
Verified
Journal Article
Closed access
PDF file
LBLaurenţiu Bubuianu
Laurenţiu Bubuianu
KIKlee Irwin
Klee Irwin
SVSergiu Vacaru
Sergiu Vacaru
Heterotic supergravity with (1 + 3)-dimensional domain wall configurations and (warped) internal, six dimensional, almost-Kähler manifolds 6 X are studied. Considering ten dimensional spacetimes with nonholonomic distributions and conventional double fibrations, 2 + 2 + ... = 2 + 2 + 3 + 3, and associated SU (3) structures on internal space, we generalize for real, internal, almost symplectic gravitational structures the constructions with gravitational and gauge instantons of tanh-kink type [1, 2]. They include the first α ′ corrections to the heterotic supergravity action, parameterized in a form to imply nonholonomic deformations of the Yang–Mills sector and corresponding Bianchi identities. We show how it is possible to construct a variety of solutions depending on the type of nonholonomic distributions and deformations of ‘prime’ instanton configurations characterized by two real supercharges. This corresponds to N = 1 / 2 supersymmetric, nonholonomic manifolds from the four dimensional point of view. Our method provides a unified description of embedding nonholonomically deformed tanh-kink-type instantons into half-BPS solutions of heterotic supergravity. This allows us to elaborate new geometric methods of constructing exact solutions of motion equations, with first order α ′ corrections to the heterotic supergravity. Such a formalism is applied for general and/or warped almost-Kähler configurations, which allows us to generate nontrivial (1 + 3)-d domain walls and black hole deformations determined by quasiperiodic internal space structures. This formalism is utilized in our associated publication [3] in order to construct and study generic off-diagonal nonholonomic deformations of the Kerr metric, encoding contributions from heterotic supergravity.

9 October 2017 in Crystals
Verified
Journal Article
Open access
PDF file
FFFang Fang
Fang Fang
DHDugan Hammock
Dugan Hammock
KIKlee Irwin
Klee Irwin
This paper reviews the empire problem for quasiperiodic tilings and the existing methods for generating the empires of the vertex configurations in quasicrystals, while introducing a new and more efficient method based on the cut-and-project technique. Using Penrose tiling as an example, this method finds the forced tiles with the restrictions in the high dimensional lattice (the mother lattice) that can be cut-and-projected into the lower dimensional quasicrystal. We compare our method to the two existing methods, namely one method that uses the algorithm of the Fibonacci chain to force the Ammann bars in order to find the forced tiles of an empire and the method that follows the work of N.G. de Bruijn on constructing a Penrose tiling as the dual to a pentagrid. This new method is not only conceptually simple and clear, but it also allows us to calculate the empires of the vertex configurations in a defected quasicrystal by reversing the configuration of the quasicrystal to its higher dimensional lattice, where we then apply the restrictions. These advantages may provide a key guiding principle for phason dynamics and an important tool for self error-correction in quasicrystal growth.

9 January 2017 in The European Physical Journal C
Verified
Journal Article
Open access
PDF file
SVSergiu Vacaru
Sergiu Vacaru
KIKlee Irwin
Klee Irwin
Geometric methods for constructing exact solutions of equations of motion with first order \(\alpha ^{\prime }\) corrections to the heterotic supergravity action implying a nontrivial Yang–Mills sector and six-dimensional, 6-d, almost-Kähler internal spaces are studied. In 10-d spacetimes, general parametrizations for generic off-diagonal metrics, nonlinear and linear connections, and matter sources, when the equations of motion decouple in very general forms are considered. This allows us to construct a variety of exact solutions when the coefficients of fundamental geometric/physical objects depend on all higher-dimensional spacetime coordinates via corresponding classes of generating and integration functions, generalized effective sources and integration constants. Such generalized solutions are determined by generic off-diagonal metrics and nonlinear and/or linear connections; in particular, as configurations which are warped/compactified to lower dimensions and for Levi-Civita connections. The corresponding metrics can have (non-) Killing and/or Lie algebra symmetries and/or describe \((1+2)\)-d and/or \((1+3)\)-d domain wall configurations, with possible warping nearly almost-Kähler manifolds, with gravitational and gauge instantons for nonlinear vacuum configurations and effective polarizations of cosmological and interaction constants encoding string gravity effects. A series of examples of exact solutions describing generic off-diagonal supergravity modifications to black hole/ellipsoid and solitonic configurations are provided and analyzed. We prove that it is possible to reproduce the Kerr and other type black solutions in general relativity (with certain types of string corrections) in the 4-d case and to generalize the solutions to non-vacuum configurations in (super-) gravity/string theories.

19 December 2018 in Symmetry
Verified
Journal Article
Open access
PDF file
Michel PlanatMichel Planat
Michel Planat
RARaymond Aschheim
Raymond Aschheim
MAMarcelo Amaral
Marcelo Amaral
KIKlee Irwin
Klee Irwin
A single qubit may be represented on the Bloch sphere or similarly on the 3-sphere S 3 . Our goal is to dress this correspondence by converting the language of universal quantum computing (UQC) to that of 3-manifolds. A magic state and the Pauli group acting on it define a model of UQC as a positive operator-valued measure (POVM) that one recognizes to be a 3-manifold M 3 . More precisely, the d-dimensional POVMs defined from subgroups of finite index of the modular group P S L ( 2 , Z ) correspond to d-fold M 3 - coverings over the trefoil knot. In this paper, we also investigate quantum information on a few ‘universal’ knots and links such as the figure-of-eight knot, the Whitehead link and Borromean rings, making use of the catalog of platonic manifolds available on the software SnapPy. Further connections between POVMs based UQC and M 3 ’s obtained from Dehn fillings are explored.

21 August 2017 in Classical and Quantum Gravity
Verified
Journal Article
Open access
PDF file
MAMarcelo Amaral
Marcelo Amaral
RARaymond Aschheim
Raymond Aschheim
LBLaurenţiu Bubuianu
Laurenţiu Bubuianu
KIKlee Irwin
Klee Irwin
SVSergiu Vacaru
Sergiu Vacaru
DWDaniel Woolridge
Daniel Woolridge
The goal of this work is to elaborate on new geometric methods of constructing exact and parametric quasiperiodic solutions for anamorphic cosmology models in modified gravity theories, MGTs, and general relativity, GR. There exist previously studied generic off-diagonal and diagonalizable cosmological metrics encoding gravitational and matter fields with quasicrystal like structures, QC, and holonomy corrections from loop quantum gravity, LQG. We apply the anholonomic frame deformation method, AFDM, in order to decouple the (modified) gravitational and matter field equations in general form. This allows us to find integral varieties of cosmological solutions determined by generating functions, effective sources, integration functions and constants. The coefficients of metrics and connections for such cosmological configurations depend, in general, on all spacetime coordinates and can be chosen to generate observable (quasi)-periodic/aperiodic/fractal/stochastic/(super) cluster/filament/polymer like (continuous, stochastic, fractal and/or discrete structures) in MGTs and/or GR. In this work, we study new classes of solutions for anamorphic cosmology with LQG holonomy corrections. Such solutions are characterized by nonlinear symmetries of generating functions for generic off-diagonal cosmological metrics and generalized connections, with possible nonholonomic constraints to Levi–Civita configurations and diagonalizable metrics depending only on a time like coordinate. We argue that anamorphic quasiperiodic cosmological models integrate the concept of quantum discrete spacetime, with certain gravitational QC-like vacuum and nonvacuum structures. And, that of a contracting universe that homogenizes, isotropizes and flattens without introducing initial conditions or multiverse problems.

1 February 2019 in Computational Materials Science
Verified
Journal Article
Closed access
VDVladimir Dubinko
Vladimir Dubinko
DLDenis Laptev
Denis Laptev
DTDmitry Terentyev
Dmitry Terentyev
SDSergey V. Dmitriev
Sergey V. Dmitriev
KIKlee Irwin
Klee Irwin