1,892 research outputs found
Some integrable models in quantized spaces
It is shown that in a quantized space determined by the algebra with three dimensional parameters of the length ,
momentum , and action , the spectrum of the Coulomb problem with
conserving Runge-Lenz vector coincides with the spectrum found by Schr\"odinger
for the space of constant curvature but with the values of the principal
quantum number limited from the side of higher values. The same problem is
solved for the spectrum of a harmonic oscillator.Comment: 11 pages, LaTe
Updated Analysis of a_1 and a_2 in Hadronic Two-body Decays of B Mesons
Using the recent experimental data of , , and various model calculations on form
factors, we re-analyze the effective coefficients a_1 and a_2 and their ratio.
QCD and electroweak penguin corrections to a_1 from and
a_2 from are estimated. In addition to the
model-dependent determination, the effective coefficient a_1 is also extracted
in a model-independent way as the decay modes are related by
factorization to the measured semileptonic distribution of at . Moreover, this enables us to extract model-independent
heavy-to-heavy form factors, for example,
and
. The determination of the magnitude of
a_2 from depends on the form factors ,
and at . By requiring that a_2 be
process insensitive (i.e., the value of a_2 extracted from and
states should be similar), as implied by the factorization
hypothesis, we find that form factors are severely constrained;
they respect the relation . Form factors and at
inferred from the measurements of the longitudinal
polarization fraction and the P-wave component in are
obtained. A stringent upper limit on a_2 is derived from the current bound on
\ov B^0\to D^0\pi^0 and it is sensitive to final-state interactions.Comment: 33 pages, 2 figures. Typos in Tables I and IX are corrected. To
appear in Phys. Rev.
--geometry of the Toda systems associated with non-exceptional simple Lie algebras
The present paper describes the --geometry of the Abelian finite
non-periodic (conformal) Toda systems associated with the and series
of the simple Lie algebras endowed with the canonical gradation. The principal
tool here is a generalization of the classical Pl\"ucker embedding of the
-case to the flag manifolds associated with the fundamental representations
of , and , and a direct proof that the corresponding K\"ahler
potentials satisfy the system of two--dimensional finite non-periodic
(conformal) Toda equations. It is shown that the --geometry of the type
mentioned above coincide with the differential geometry of special holomorphic
(W) surfaces in target spaces which are submanifolds (quadrics) of with
appropriate choices of . In addition, these W-surfaces are defined to
satisfy quadratic holomorphic differential conditions that ensure consistency
of the generalized Pl\"ucker embedding. These conditions are automatically
fulfiled when Toda equations hold.Comment: 30 pages, no figur
Gravitational anomaly and fundamental forces
I present an argument, based on the topology of the universe, why there are
three generations of fermions. The argument implies a preferred gauge group of
SU(5), but with SO(10) representations of the fermions. The breaking pattern
SU(5) to SU(3)xSU(2)xU(1) is preferred over the pattern SU(5) to SU(4)xU(1). On
the basis of the argument one expects an asymmetry in the early universe
microwave data, which might have been detected already.Comment: Contribution to the 2nd School and Workshop on Quantum Gravity and
Quantum Geometry. Corfu, september 13-20 2009. 10 page
Quantum Dynamics in Non-equilibrium Strongly Correlated Environments
We consider a quantum point contact between two Luttinger liquids coupled to
a mechanical system (oscillator). For non-vanishing bias, we find an effective
oscillator temperature that depends on the Luttinger parameter. A generalized
fluctuation-dissipation relation connects the decoherence and dissipation of
the oscillator to the current-voltage characteristics of the device. Via a
spectral representation, this result is generalized to arbitrary leads in a
weak tunneling regime.Comment: 4 pages, 1 figur
Binding energies and electronic structures of adsorbed titanium chains on carbon nanotubes
We have studied the binding energies and electronic structures of metal (Ti,
Al, Au) chains adsorbed on single-wall carbon nanotubes (SWNT) using first
principles methods. Our calculations have shown that titanium is much more
favored energetically over gold and aluminum to form a continuous chain on a
variety of SWNTs. The interaction between titanium and carbon nanotube
significantly modifies the electronic structures around Fermi energy for both
zigzag and armchair tubes. The delocalized 3d electrons from the titanium chain
generate additional states in the band gap regions of the semiconducting tubes,
transforming them into metals.Comment: 4 pages, 3 figure
Classification and nondegeneracy of Toda system with singular sources
We consider the following Toda system \Delta u_i + \D \sum_{j = 1}^n
a_{ij}e^{u_j} = 4\pi\gamma_{i}\delta_{0} \text{in}\mathbb R^2, \int_{\mathbb
R^2}e^{u_i} dx -1\delta_0a_{ij}\gamma_i=0\forall \;1\leq i\leq n\gamma_i+\gamma_{i+1}+...+\gamma_j \notin \mathbb Z1\leq i\leq
j\leq nu_i$ is \textit{radially symmetric} w.r.t. 0.
(iii) We prove that the linearized equation at any solution is
\textit{non-degenerate}. These are fundamental results in order to understand
the bubbling behavior of the Toda system.Comment: 28 page
Analytic Bethe Ansatz for Fundamental Representations of Yangians
We study the analytic Bethe ansatz in solvable vertex models associated with
the Yangian or its quantum affine analogue for and . Eigenvalue formulas are proposed for the transfer matrices
related to all the fundamental representations of . Under the Bethe
ansatz equation, we explicitly prove that they are pole-free, a crucial
property in the ansatz. Conjectures are also given on higher representation
cases by applying the -system, the transfer matrix functional relations
proposed recently. The eigenvalues are neatly described in terms of Yangian
analogues of the semi-standard Young tableaux.Comment: 45 pages, Plain Te
Dilogarithm Identities in Conformal Field Theory and Group Homology
Recently, Rogers' dilogarithm identities have attracted much attention in the
setting of conformal field theory as well as lattice model calculations. One of
the connecting threads is an identity of Richmond-Szekeres that appeared in the
computation of central charges in conformal field theory. We show that the
Richmond-Szekeres identity and its extension by Kirillov-Reshetikhin can be
interpreted as a lift of a generator of the third integral homology of a finite
cyclic subgroup sitting inside the projective special linear group of all real matrices viewed as a {\it discrete} group. This connection
allows us to clarify a few of the assertions and conjectures stated in the work
of Nahm-Recknagel-Terhoven concerning the role of algebraic -theory and
Thurston's program on hyperbolic 3-manifolds. Specifically, it is not related
to hyperbolic 3-manifolds as suggested but is more appropriately related to the
group manifold of the universal covering group of the projective special linear
group of all real matrices viewed as a topological group. This
also resolves the weaker version of the conjecture as formulated by Kirillov.
We end with the summary of a number of open conjectures on the mathematical
side.Comment: 20 pages, 2 figures not include
Slowly rotating charged black holes in anti-de Sitter third order Lovelock gravity
In this paper, we study slowly rotating black hole solutions in Lovelock
gravity (n=3). These exact slowly rotating black hole solutions are obtained in
uncharged and charged cases, respectively. Up to the linear order of the
rotating parameter a, the mass, Hawking temperature and entropy of the
uncharged black holes get no corrections from rotation. In charged case, we
compute magnetic dipole moment and gyromagnetic ratio of the black holes. It is
shown that the gyromagnetic ratio keeps invariant after introducing the
Gauss-Bonnet and third order Lovelock interactions.Comment: 14 pages, no figur
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