2,874 research outputs found
Light-Ray Radon Transform for Abelianin and Nonabelian Connection in 3 and 4 Dimensional Space with Minkowsky Metric
We consider a real manifold of dimension 3 or 4 with Minkovsky metric, and
with a connection for a trivial GL(n,C) bundle over that manifold. To each
light ray on the manifold we assign the data of paralel transport along that
light ray. It turns out that these data are not enough to reconstruct the
connection, but we can add more data, which depend now not from lines but from
2-planes, and which in some sence are the data of parallel transport in the
complex light-like directions, then we can reconstruct the connection up to a
gauge transformation. There are some interesting applications of the
construction: 1) in 4 dimensions, the self-dual Yang Mills equations can be
written as the zero curvature condition for a pair of certain first order
differential operators; one of the operators in the pair is the covariant
derivative in complex light-like direction we studied. 2) there is a relation
of this Radon transform with the supersymmetry. 3)using our Radon transform, we
can get a measure on the space of 2 dimensional planes in 4 dimensional real
space. Any such measure give rise to a Crofton 2-density. The integrals of this
2-density over surfaces in R^4 give rise to the Lagrangian for maps of real
surfaces into R^4, and therefore to some string theory. 4) there are relations
with the representation theory. In particular, a closely related transform in 3
dimensions can be used to get the Plancerel formula for representations of
SL(2,R).Comment: We add an important discussion part, establishing the relation of our
Radon transform with the self-dual Yang-Mills, string theory, and the
represntation theory of the group SL(2,R
SU(3) Anderson impurity model: A numerical renormalization group approach exploiting non-Abelian symmetries
We show how the density-matrix numerical renormalization group (DM-NRG)
method can be used in combination with non-Abelian symmetries such as SU(N),
where the decomposition of the direct product of two irreducible
representations requires the use of a so-called outer multiplicity label. We
apply this scheme to the SU(3) symmetrical Anderson model, for which we analyze
the finite size spectrum, determine local fermionic, spin, superconducting, and
trion spectral functions, and also compute the temperature dependence of the
conductance. Our calculations reveal a rich Fermi liquid structure.Comment: 18 pages, 9 figure
The Associated Metric for a Particle in a Quantum Energy Level
We show that the probabilistic distribution over the space in the spectator
world, can be associated via noncommutative geometry (with some modifications)
to a metric in which the particle lives. According to this geometrical view,
the metric in the particle world is ``contracted'' or ``stretched'' in an
inverse proportion to the probability distribution.Comment: 14 pages, latex, epsf, 3 figures. Some clarifications were adde
Isotropic subbundles of
We define integrable, big-isotropic structures on a manifold as
subbundles that are isotropic with respect to the
natural, neutral metric (pairing) of and are closed by
Courant brackets (this also implies that ). We give the interpretation of such a structure by objects of
, we discuss the local geometry of the structure and we give a reduction
theorem.Comment: LaTex, 37 pages, minimization of the defining condition
Noncommutative symmetric functions and Laplace operators for classical Lie algebras
New systems of Laplace (Casimir) operators for the orthogonal and symplectic
Lie algebras are constructed. The operators are expressed in terms of paths in
graphs related to matrices formed by the generators of these Lie algebras with
the use of some properties of the noncommutative symmetric functions associated
with a matrix. The decomposition of the Sklyanin determinant into a product of
quasi-determinants play the main role in the construction. Analogous
decomposition for the quantum determinant provides an alternative proof of the
known construction for the Lie algebra gl(N).Comment: 25 page
Tree-level scattering amplitudes from the amplituhedron
7 pages, 2 figures, to be published in the Journal of Physics: Conference Series. Proceedings for the "7th Young Researcher Meeting", Torino, 2016A central problem in quantum field theory is the computation of scattering amplitudes. However, traditional methods are impractical to calculate high order phenomenologically relevant observables. Building on a few decades of astonishing progress in developing non-standard computational techniques, it has been recently conjectured that amplitudes in planar N=4 super Yang-Mills are given by the volume of the (dual) amplituhedron. After providing an introduction to the subject at tree-level, we discuss a special class of differential equations obeyed by the corresponding volume forms. In particular, we show how they fix completely the amplituhedron volume for next-to-maximally helicity violating scattering amplitudes.Peer reviewe
The twistor geometry of three-qubit entanglement
A geometrical description of three qubit entanglement is given. A part of the
transformations corresponding to stochastic local operations and classical
communication on the qubits is regarded as a gauge degree of freedom. Entangled
states can be represented by the points of the Klein quadric a space
known from twistor theory. It is shown that three-qubit invariants are
vanishing on special subspaces of . An invariant vanishing for the
class is proposed. A geometric interpretation of the canonical
decomposition and the inequality for distributed entanglement is also given.Comment: 4 pages RevTeX
Quantum Sturm-Liouville Equation, Quantum Resolvent, Quantum Integrals, and Quantum KdV : the Fast Decrease Case
We construct quantum operators solving the quantum versions of the
Sturm-Liouville equation and the resolvent equation, and show the existence of
conserved currents. The construction depends on the following input data: the
basic quantum field and the regularization .Comment: minor correction
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