44,558 research outputs found
Intensity Scintillation and Astronomical Quantum Observation
Holography is 3D imaging which can record intensity and phase at the same
time. The importance of construct hologram is holographic recording and
wavefront reconstruction. It is surprised that holography be discovered in
study interstellar scintillation for pulsar provide a coherent light source
recently. I think that is speckle hologram and speckle interference(i.e.
intensity interference), and use modern technique which include phased
array,CCD, digital signal processing and supercomputer can achieve that digital
and computer holography from radio to X-ray astronomy. This means we can use it
to image the universe and beyond the limited of telescope for cosmos provide
much coherent light from pulsar,maser, black hole to 21cm recombination line.
It gives a probe to the medium of near the black hole et al. From those
coherent light sources in the sky, we can uncover one different universe that
through astronomical quantum observation which use intensity interference.Comment: submitte
Cyclostationary in the Time Variable Universe
Cyclostationary processes are those signals whose have vary almost
periodically in statistics. It can give rise to random data whose statistical
characteristics vary periodically with time although these processes not
periodic functions of time. Intermittent pulsar is a special type in pulsar
astronomy which have period but not a continuum. The Rotating RAdio TransientS
(RRATs) represent a previously unknown population of bursting neutron stars.
Cyclical period changes of variables star also can be thought as
cyclostationary which are several classes of close binary systems.
Quasi-Periodic Oscillations (QPOs) refer to the way the X-ray light from an
astronomical object flickers about certain frequencies in high-energy (X-ray)
astronomy. I think that all above phenomenon is cyclostationary process. I
describe the signal processing of cyclostationary, then discussed that the
relation between it and intermittent pulsar, RRATs, cyclical period changes of
variables star and QPOs, and give the perspective of finding the
cyclostationary source in the transient universe.Comment: Submitte
Rationality of vertex operator algebras
It is shown that a simple vertex operator algebra V is rational if and only
if its Zhu algebra A(V) is semisimple and each irreducible admissible V-module
is ordinary. A contravariant form on a Verma type admissible V-module is
constructed and the radical is exactly the maximal proper submodule. As an
application the rationality of V_L^+ for any positive definite even lattice is
obtained.Comment: 33page
Bimodules associated to vertex operator algebras
Let V be a vertex operator algebra and m,n be nonnegative integers. We
construct an A_n(V)-A_m(V)-bimodule A_{n,m}(V) which determines the action of V
from the level m subspace to level n subspace of an admissible V-module. We
show how to use A_{n,m}(V) to construct naturally admissible V-modules from
A_m(V)-modules. We also determine the structure of A_{n,m}(V) when V is
rational.Comment: a minor chang
Representations of the vertex operator algebra V_{L_{2}}^{A_{4}}
The rationality and C_2-cofiniteness of the orbifold vertex operator algebra
V_{L_{2}}^{A_{4}} are established and all the irreducible modules are
constructed and classified. This is part of classification of rational vertex
operator algebras with c=1.Comment: 24 pages, a correction of Lemma 5.
A characterization of the rational vertex operator algebra }: II
A characterization of vertex operator algebra for any rank one
positive definite even lattice is given in terms of dimensions of
homogeneous subspaces of small weights. This result reduces the classification
of rational vertex operator algebras of central charge 1 to the
characterization of three vertex operator algebras in the -series of central
charge one.Comment: 32 page
A characterization of the vertex operator algebra
The rational vertex operator algebra is characterized in
terms of weights of primary vectors. This reduces the classification of
rational vertex operator algebras with to the characterizations of
and Comment: 19 pages, published versio
Bimodules and g-rationality of vertex operator algebras
This paper studies the twisted representations of vertex operator algebras.
Let V be a vertex operator algebra and g an automorphism of V of finite order
T. For any m,n in (1/T)Z_+, an A_{g,n}(V)-A_{g,m}(V)-bimodule A_{g,n,m}(V) is
constructed. The collection of these bimodules determines any admissible
g-twisted V-module completely. A Verma type admissible g-twisted V-module is
constructed naturally from any A_{g,m}(V)-module. Furthermore, it is shown with
the help of bimodule theory that a simple vertex operator algebra V is
g-rational if and only if its twisted associative algebra A_g(V) is semisimple
and each irreducible admissible g-twisted V-module is ordinary.Comment: 32 page
Representations of vertex operator algebras
This paper is an exposition of the representation theory of vertex operator
algebras in terms of associative algebras A_n(V) and their bimodules. A new
result on the rationality is given. That is, a simple vertex operator algebra V
is rational if and only if its Zhu algebra A(V) is a semisimple associative
algebra and each irreducible admissible -module is ordinary.Comment: 13 pages, final version for publicatio
Quantum Atmospherics for Materials Diagnosis
Symmetry breaking states of matter can transmit symmetry breaking to nearby
atoms or molecular complexes, perturbing their spectra. We calculate one such
effect, involving the `axion electrodynamics' relevant to topological
insulators, quantitatively, and identify a signature for T violating
superconductivity. We provide an operator framework whereby effects of this
kind can be analyzed systematically.Comment: Includes several stylistic changes and minor additions, plus
significant new material on (chiral) superconductors. Published versio
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