7,486 research outputs found
Intertwined Hamiltonians in Two Dimensional Curved Spaces
The problem of intertwined Hamiltonians in two dimensional curved spaces is
investigated. Explicit results are obtained for Euclidean plane,Minkowski
plane, Poincar{\' e} half plane (), de Sitter Plane (), sphere,
and torus. It is shown that the intertwining operator is related to the Killing
vector fields and the isometry group of corresponding space. It is shown that
the intertwined potentials are closely connected to the integral curves of the
Killing vector fields. Two problems of considered as applications of the
formalism presented in the paper. The first one is the problem of Hamiltonians
with equispaced energy levels and the second one is the problem of Hamiltonians
whose spectrum are like the spectrum of a free particle.Comment: To appear in Annals of Physic
Warped Entanglement Entropy
We study the applicability of the covariant holographic entanglement entropy
proposal to asymptotically warped AdS spacetimes with an SL(2,R) x U(1)
isometry. We begin by applying the proposal to locally AdS backgrounds
which are written as a real-line fibration over AdS. We then perturb away
from this geometry by considering a warping parameter to get an
asymptotically warped AdS spacetime and compute the dual entanglement
entropy perturbatively in . We find that for large separation in the
fiber coordinate, the entanglement entropy can be computed to all orders in
and takes the universal form appropriate for two-dimensional CFTs. The
warping-dependent central charge thus identified exactly agrees with previous
calculations in the literature. Performing the same perturbative calculations
for the warped BTZ black hole again gives universal two-dimensional CFT
answers, with the left-moving and right-moving temperatures appearing
appropriately in the result.Comment: 25 pages plus appendices; v2 references added, discussions clarified
and equations sharpene
Lifshitz black holes in higher spin gravity
We study asymptotically Lifshitz solutions to three dimensional higher spin
gravity in the SL(3,R)xSL(3,R) Chern-Simons formulation. We begin by specifying
the most general connections satisfying Lifshitz boundary conditions, and we
verify that their algebra of symmetries contains a Lifshitz sub-algebra. We
then exhibit connections that can be viewed as higher spin Lifshitz black
holes. We show that when suitable holonomy conditions are imposed, these black
holes obey sensible thermodynamics and possess a gauge in which the
corresponding metric exhibits a regular horizon.Comment: 34 pages, LaTeX, 10 figures, v2: minor edits, 2 new reference
The effects of pictures on the order of accessing online war stories
Research on how people read news stories has shown that readers chose to read and access news stories associated with pictures that contained an element of attraction. Researchers have found that the emotional elements within the picture could also play a role. It is unclear how neutral human interest pictures influence readers to access news stories. Is the access process influenced by less emotive pictures or more human interest elements? These issues were explored in an experiment in which 24 students participated. The experiment compared similar news that was accompanied with a human interest picture, information graphic and without information graphic. The focus of the news stories was on war news which almost always contained human interest elements that could be neutral or emotion-laden. The experiment suggested that human interest pictures of war stories could be equally effective in attracting readers to read and remember the news stories
On the Statistical Origin of Topological Symmetries
We investigate a quantum system possessing a parasupersymmetry of order 2, an
orthosupersymmetry of order , a fractional supersymmetry of order , and
topological symmetries of type and . We obtain the
corresponding symmetry generators, explore their relationship, and show that
they may be expressed in terms of the creation and annihilation operators for
an ordinary boson and orthofermions of order . We give a realization of
parafermions of order~2 using orthofermions of arbitrary order , discuss a
parasupersymmetry between parafermions and parabosons of arbitrary
order, and show that every orthosupersymmetric system possesses topological
symmetries. We also reveal a correspondence between the orthosupersymmetry of
order and the fractional supersymmetry of order .Comment: 12 page
Topological Symmetries
We introduce the notion of a topological symmetry as a quantum mechanical
symmetry involving a certain topological invariant. We obtain the underlying
algebraic structure of the Z_2-graded uniform topological symmetries of type
(1,1) and (2,1). This leads to a novel derivation of the algebras of
supersymmetry and parasupersummetry.Comment: Plain LaTeX Ref: Mod. Phys. Lett. A 15, 175-184 (2000
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