arXiv subjects

C. H. Oh

Publications and source records attributed to C. H. Oh.

179 records · Page 10Linked to original sources

arXiv2000

Noncyclic geometric phase for neutrino oscillation

We provide explicit formulae for the noncyclic geometric phases or Pancharatnam phases of neutrino oscillations. Since Pancharatnam phase is a generalization of the Berry phase, our results generalize the previous findings for Berry phase in a recent paper [Phys. Lett. B, 466 (1999) 262]. Unlike the Berry phase, the noncyclic geometric phase offers distinctive advantage in terms of measurement and prediction. In particular, for three-flavor mixing, our explicit formula offers an alternative means of determining the CP-violating phase. Our results can also be extended easily to explore geometric phase associated with neutron-antineutron oscillations.

hep-ph↗

arXiv1999

On Bures fidelity of displaced squeezed thermal states

Fidelity plays a key role in quantum information and communication theory. Fidelity can be interpreted as the probability that a decoded message possesses the same information content as the message prior to coding and transmission. In this paper, we give a formula of Bures fidelity for displaced squeezed thermal states directly by the displacement and squeezing parameters and birefly discuss how the results can apply to quantum information theory.

quant-ph↗

arXiv1998

General Approach to Functional Forms for the Exponential Quadratic Operators in Coordinate-Momentum Space

In a recent paper [Nieto M M 1996 Quantum and Semiclassical Optics, 8 1061; quant-ph/9605032], the one dimensional squeezed and harmonic oscillator time-displacement operators were reordered in coordinate-momentum space. In this paper, we give a general approach for reordering multi-dimensional exponential quadratic operator(EQO) in coordinate-momentum space. An explicit computational formula is provided and applied to the single mode and double-mode EQO through the squeezed operator and the time displacement operator of the harmonic oscillator.

quant-ph↗

arXiv1998

A General $q$-Oscillator Algebra

It is well-known that the Macfarlane-Biedenharn $q$-oscillator and its generalization has no Hopf structure, whereas the Hong Yan $q$-oscillator can be endowed with a Hopf structure. In this letter, we demonstrate that it is possible to construct a general $q$-oscillator algebra which includes the Macfarlane-Biedenharn oscillator algebra and the Hong Yan oscillator algebra as special cases.

math.QA↗

arXiv1997

Some comments on $q$-deformed oscillators and $q$-deformed $su(2)$ algebras

The various relations between $q$-deformed oscillators algebras and the $q$-deformed $su(2)$ algebras are discussed. In particular, we exhibit the similarity of the $q$-deformed $su(2)$ algebra obtained from $q$-oscillators via Schwinger construction and those obtained from $q$-Holstein-Primakoff transformation and show how the relation between $su_{\sqrt{q}}(2)$ and Hong Yan $q$-oscillator can be regarded as an special case of Inöuë- Wigner contraction. This latter observation and the imposition of positive norm requirement suggest that Hong-Yan $q$-oscillator algebra is different from the usual $su_{\sqrt{q}}(2)$ algebra, contrary to current belief in the literature.

q-alg↗

arXiv1997

Nucleon-Nucleon Partial Wave Analysis to 2.5 GeV

A partial-wave analysis of NN elastic scattering data has been completed. This analysis covers an expanded energy range, from threshold to a laboratory kinetic energy of 2.5 GeV, in order to include recent elastic pp scattering data produced by the EDDA collaboration at COSY. The results of both single-energy and energy-dependent analyses are described.

nucl-th↗

arXiv1997

q-Deformation of the Krichever-Novikov Algebra

The recent focus on deformations of algebras called quantum algebras can be attributed to the fact that they appear to be the basic algebraic structures underlying an amazingly diverse set of physical situations. To date many interesting features of these algebras have been found and they are now known to belong to a class of algebras called Hopf algebras [1]. The remarkable aspect of these structures is that they can be regarded as deformations of the usual Lie algebras. Of late, there has been a considerable interest in the deformation of the Virasoro algebra and the underlying Heisenberg algebra [2-11]. In this letter we focus our attention on deforming generalizations of these algebras, namely the Krichever-Novikov (KN) algebra and its associated Heisenberg algebra.

q-alg↗

arXiv1997

Nucleon-nucleon elastic scattering analysis to 2.5 GeV

A partial-wave analysis of NN elastic scattering data has been completed. This analysis covers an expanded energy range, from threshold to a laboratory kinetic energy of 2.5 GeV, in order to include recent elastic pp scattering data from the EDDA collaboration. The results of both single-energy and energy-dependent analyses are described.

nucl-th↗

arXiv1997

A Schwinger term in q-deformed su(2) algebra

An extra term generally appears in the q-deformed $su(2)$ algebra for the deformation parameter $q = \exp{ 2 πiθ}$, if one combines the Biedenharn-Macfarlane construction of q-deformed $su(2)$, which is a generalization of Schwinger's construction of conventional $su(2)$, with the representation of the q-deformed oscillator algebra which is manifestly free of negative norm. This extra term introduced by the requirement of positive norm is analogous to the Schwinger term in current algebra. Implications of this extra term on the Bloch electron problem analyzed by Wiegmann and Zabrodin are briefly discussed.

hep-th↗

arXiv1996

Symmetric Multiplets in Quantum Algebras

We consider a modified version of the coproduct for $\U(\su_q(2))$ and show that in the limit when $q \rightarrow 1$, there exists an essentially non-cocommutative coproduct. We study the implications of this non-cocommutativity for a system of two spin-$1/2$ particles. Here it is shown that, unlike the usual case, this non-trivial coproduct allows for symmetric and anti-symmetric states to be present in the multiplet. We surmise that our analysis could be related to the ferromagnetic and antiferromagnetic cases of the Heisenberg magnets.

q-alg↗

arXiv1995

Two-State Spectral-Free Solutions of Frenkel-Moore Simplex Equation

Whilst many solutions have been found for the Quantum Yang-Baxter Equation (QYBE), there are fewer known solutions available for its higher dimensional generalizations: Zamolodchikov's tetrahedron equation (ZTE) and Frenkel and Moore's simplex equation (FME). In this paper, we present families of solutions to FME which may help us to understand more about higher dimensional generalization of QYBE.

hep-th↗

arXiv1995

A Labelling Scheme for Higher Dimensional Simplex Equations

We present a succinct way of obtaining all possible higher dimensional generalization of Quantum Yang-Baxter Equation (QYBE). Using the scheme, we could generate the two popular three-simplex equations, namely: Zamolodchikov's tetrahedron equation (ZTE) and Frenkel and Moore equation (FME).

hep-th↗

arXiv1995

Q-Deformed Oscillator Algebra and an Index Theorem for the Photon Phase Operator

The quantum deformation of the oscillator algebra and its implications on the phase operator are studied from a view point of an index theorem by using an explicit matrix representation. For a positive deformation parameter $q$ or $q=exp(2πiθ)$ with an irrational $θ$, one obtains an index condition $\dml a - \dml a^{\dagger} = 1$ which allows only a non-hermitian phase operator with $\dml \expon^{i φ} - \dml (\expon^{iφ})^{\dagger} = 1$. For $q=exp(2πiθ)$ with a rational $θ$ , one formally obtains the singular situation $\dml a =\infty$ and $ \dml a^{\dagger} = \infty$, which allows a hermitian phase operator with $\dml \expon^{i Φ} - \dml (\expon^{iΦ})^{\dagger} = 0$ as well as the non-hermitian one with $\dml \expon^{i φ} - \dml (\expon^{iφ})^{\dagger} = 1$. Implications of this interpretation of the quantum deformation are discussed. We also show how to overcome the problem of negative norm for $q=exp(2πiθ)$.

hep-th↗

arXiv1994

Realizations of the $q$-Heisenberg and $q$-Virasoro Algebras

We give field theoretic realizations of both the $q$-Heisenberg and the $q$-Virasoro algebra. In particular, we obtain the operator product expansions among the current and the energy momentum tensor obtained using the Sugawara construction.

hep-th↗

arXiv1994

Constraints and Period Relations in Bosonic Strings at Genus-g

We examine some of the implications of implementing the usual boundary conditions on the closed bosonic string in the hamiltonian framework. Using the KN formalism, it is shown that at the quantum level, the resulting constraints lead to relations among the periods of the basis 1-forms. These are compared with those of Riemanns' which arise from a different consideration.

hep-th↗

arXiv1994

Generalized q-Oscillators and their Hopf Structures

We study the relationships among the various forms of the $q$ oscillator algebra and consider the conditions under which it supports a Hopf structure. We also present a generalization of this algebra together with its corresponding Hopf structure. Its multimode extensions are also considered.

hep-th↗

arXiv1994

Conformal Properties of Primary Fields in a q-Deformed Theory

We examine some of the standard features of primary fields in the framework of a $q$-deformed conformal field theory. By introducing a $q$-OPE between the energy momentum tensor and a primary field, we derive the $q$-analog of the conformal Ward identities for correlation functions of primary fields. We also obtain solutions to these identities for the two-point function.

hep-th↗