Modern Physics Letters A

We investigate a quantum system possessing a parasupersymmetry of order 2, an orthosupersymmetry of order p, a fractional supersymmetry of order p+1, and topological symmetries of type (1,p) and (1,1,…,1). We obtain the corresponding symmetry generators, explore their relationship, and show that they may be expressed in terms of the creation and annihilation operators for an ordinary boson and orthofermions of order p. We give a realization of parafermions of order 2 using orthofermions of arbitrary order p, discuss a p=2 parasupersymmetry between p = 2 parafermions and parabosons of arbitrary order, and show that every orthosupersymmetric system possesses topological symmetries. We also reveal a correspondence between the orthosupersymmetry of order p and the fractional supersymmetry of order p+1.

We study field theories defined in regions of the spatial noncommutative (NC) plane with a boundary present delimiting them, concentrating in particular on the U(1) NC Chern–Simons theory on the upper half-plane. We find that classical consistency and gauge invariance lead necessary to the introduction of K₀-space of square integrable functions null together with all their derivatives at the origin. Furthermore the requirement of closure of K₀ under the *-product leads to the introduction of a novel notion of the *-product itself in regions where a boundary is present, that in turn yields the complexification of the gauge group and to consider chiral waves in one sense or other. The canonical quantization of the theory is sketched identifying the physical states and the physical operators. These last ones include ordinary NC Wilson lines starting and ending on the boundary that yield correlation functions depending on points on the one-dimensional boundary. We finally extend the definition of the *-product to a strip and comment on possible relevance of these results to finite quantum Hall systems.

The energy–momentum complexes of Einstein, Landau–Lifshitz, Papapetrou, and Weinberg give the same and meaningful results for the energy and momentum of the Bonnor space–time describing the gravitational field of a stationary beam of light. The results support the Cooperstock hypothesis.

It is pointed out that the omission of the effects of the transition between quarkonia or the assumption that the transition between quarkonia is flavor-independent would result in the inconsistent results for the pseudoscalar meson nonet. It is emphasized that the mass relation of the non-ideal mixing meson nonets should incorporate the effects of the flavor-dependent transition between quarkonia. The new mass relations of a meson nonet are presented.

It is shown that the lasing mechanism of axion solitonic stars found by Tkachev is suppressed above a critical value of the QCD decay constant f_a ≈ 10¹⁵GeV. This means, in particular, that the heterotic superstring axion mini-star — for which theory , where λ ≡ f_B/f_A is the ratio of the decay constants of the second and model-independent axions, respectively, and is the strong-interaction coupling — is allowed to form, the laser amplification being exp A, where . Relaxation may occur either by the "gravitational cooling" proposed by Seidel and Suen, and by Khlebnikov, and/or by the four-axion self-interaction studied by Tkachev.

We study a varying electric charge brane world cosmology in the RS2 model obtained from a varying-speed-of-light brane world cosmology by redefining the system of units. We elaborate conditions under which the flatness problem and the cosmological constant problem can be resolved by such cosmological model.

In the framework of superfield formalism, we demonstrate the existence of a new local, covariant, continuous and nilpotent (dual-BRST) symmetry for the BRST invariant Lagrangian density of a self-interacting two (1+1)-dimensional (2D) non-Abelian gauge theory (having no interaction with matter fields). The local and nilpotent Noether conserved charges corresponding to the above continuous symmetries find their geometrical interpretation as the translation generators along the odd (Grassmannian) directions of the four (2+2)-dimensional compact supermanifold.