20,775 research outputs found
A Hardy's Uncertainty Principle Lemma in Weak Commutation Relations of Heisenberg-Lie Algebra
In this article we consider linear operators satisfying a generalized
commutation relation of a type of the Heisenberg-Lie algebra. It is proven that
a generalized inequality of the Hardy's uncertainty principle lemma follows.
Its applications to time operators and abstract Dirac operators are also
investigated
Comments on N = 2 supersymmetric sigma models in projective superspace
For the most general off-shell N = 2 supersymmetric sigma model in projective
superspace, we elaborate on its formulation in terms of N = 1 chiral
superfields. A universal (model-independent) expression is obtained for the
holomorphic symplectic two-form, which determines the second supersymmetry
transformation. This two-form is associated with the two complex structures of
the hyperkahler target space, which are complimentary to the one used to
realize the target space as a Kahler manifold.Comment: 7 pages; V2: reference [18] correcte
Distinguished self-adjoint extensions of Dirac operators via Hardy-Dirac inequalities
We prove some Hardy-Dirac inequalities with two different weights including
measure valued and Coulombic ones. Those inequalities are used to construct
distinguished self-adjoint extensions of Dirac operators for a class of
diagonal potentials related to the weights in the above mentioned inequalities.Comment: 16 page
The minimal B-L model naturally realized at TeV scale
In a previous paper, we have proposed the minimal B-L extended standard model
as a phenomenologically viable model that realizes the Coleman-Weinberg-type
breaking of the electroweak symmetry. Assuming the classical conformal
invariance and stability up to the Planck scale, we will show in this paper
that the model naturally predicts TeV scale B-L breaking as well as a light
standard-model singlet Higgs boson and light right-handed neutrinos around the
same energy scale. We also study phenomenology and detectability of the model
at the Large Hadron Collider (LHC) and the International Linear Collider (ILC).Comment: 24pages, 8figure
Effects of unparticle on top spin correlation at the Large Hadron Collider
We study effects of the scale invariant hidden sector, unparticle, proposed
by Georgi, on top spin correlation at the Large Hadron Collider. Assuming no
flavor changing interaction between the unparticles and the Standard Model
particles, there arises the top-antitop quark pair production process through
virtual unparticle exchanges in the s-channel in addition to the Standard Model
processes. In particular, we consider contributions of scalar and vector
unparticles and find that these make sizable deviations of the top spin
correlation from the Standard Model one.Comment: 29 pages, 1 table, 12 figures, 2 figures added, typos in captions
corrected, version accepted for publication in PR
Quantum Hall effects of graphene with multi orbitals: Topological numbers, Boltzmann conductance and Semi-classical quantization
Hall conductance as the Chern numbers of the Berry connection
in the magnetic Brillouin zone is calculated for a realistic multi band
tight-band model of graphene with non-orthogonal basis. It is confirmed that
the envelope of coincides with a semi-classical result when
magnetic field is sufficiently small.
The Hall resistivity from the weak-field Boltzmann theory also
explains the overall behaviour of the if the Fermi surface is
composed of a single energy band. The plateaux of are explained
from semi-classical quantization and necessary modification is proposed for the
Dirac fermion regimes.Comment: 5pages, 3figure
Matrix representation of the time operator
In quantum mechanics the time operator satisfies the commutation
relation , and thus it may be thought of as being canonically
conjugate to the Hamiltonian . The time operator associated with a given
Hamiltonian is not unique because one can replace by , where satisfies the homogeneous condition
. To study this nonuniqueness the matrix elements of
for the harmonic-oscillator Hamiltonian are calculated in the
eigenstate basis. This calculation requires the summation of divergent series,
and the summation is accomplished by using zeta-summation techniques. It is
shown that by including appropriate homogeneous contributions, the matrix
elements of simplify dramatically. However, it is still not clear
whether there is an optimally simple representation of the time operator.Comment: 13 pages, 3 figure
Meta-stable Vacuum in Spontaneously Broken N=2 Supersymmetric Gauge Theory
We consider an N=2 supersymmetric SU(2) \times U(1) gauge theory with N_f=2
massless flavors and a Fayet-Iliopoulos (FI) term. In the presence of the FI
term, supersymmetry is spontaneously broken at tree level (on the Coulomb
branch), leaving a pseudo-flat direction in the classical potential. This
vacuum degeneracy is removed once quantum corrections are taken into account.
Due to the SU(2) gauge dynamics, the effective potential exhibits a local
minimum at the dyon point, where not only supersymmetry but also U(1)_R
symmetry is broken, while a supersymmetric vacuum would be realized toward
infinity with the runaway behavior of the potential. This local minimum is
found to be parametrically long-lived. Interestingly, from a phenomenological
point of view, in this meta-stable vacuum the massive hypermultiplets inherent
in the theory play the role of the messenger fields in the gauge mediation
scenario, when the Standard Model gauge group is embedded into their flavor
symmetry.Comment: 27 pages, 11 figures, journal reference added, minor modifications in
the tex
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