320 research outputs found
N-enlarged Galilei Hopf algebra and its twist deformations
The N-enlarged Galilei Hopf algebra is constructed. Its twist deformations
are considered and the corresponding twisted space-times are derived.Comment: 8 pages, no figure
Twisted Rindler space-times
The (linearized) noncommutative Rindler space-times associated with
canonical, Lie-algebraic and quadratic twist-deformed Minkowski spaces are
provided. The corresponding deformed Hawking spectra detected by Rindler
observers are derived as well.Comment: 13 pages, no figures, keywords: quantum space-times, Hawking
radiatio
Reinvestigation of bisÂ(2,2âČ-bipyridine)(nitrato-Îș2 O,OâČ)cobalt(III) hydroxide nitrate tetraÂhydrate. Corrigendum
Corrigendum to Acta Cryst. (2007), E63, m2975âm2976
Twist deformation of doubly enlarged Newton-Hooke Hopf algebra
We provide fifteen twist-deformed doubly enlarged Newton-Hooke quantum
space-times. In approaching infinity limit the twisted doubly enlarged
Galilei spaces are obtained as well.Comment: 11 pages, no figures. arXiv admin note: substantial text overlap with
arXiv:1007.465
Understanding Meroitic Pottery and Its Production â Research Design and Methodology of an Interdisciplinary Research Project
This paper describes a project investigating the archaeological remains of a pottery workshop and the associated ceramics at Musawwarat es-Sufra, an archaeological site of the Meroitic period (c. 300 BCâ350 AD) in Sudan. It outlines the trajectory of a complex research approach, integrating archaeological, ceramological, archaeometric, ethnoarchaeological and geophysical components in order to make maximum use of the unique potential of the site. By discussing the setup and the trajectory of the project and how the results â expected and unexpected â of the individual components informed subsequent steps and the progress of the overall research strategy, the authors offer a contribution to the methodology of integrated research in the field of archaeological ceramic studies
Braided algebras and the kappa-deformed oscillators
Recently there were presented several proposals how to formulate the binary
relations describing kappa-deformed oscillator algebras. In this paper we shall
consider multilinear products of kappa-deformed oscillators consistent with the
axioms of braided algebras. In general case the braided triple products are
quasi-associative and satisfy the hexagon condition depending on the
coassociator . We shall consider only the products
of kappa-oscillators consistent with co-associative braided algebra, with Phi
=1. We shall consider three explicite examples of binary kappa-deformed
oscillator algebra relations and describe briefly their multilinear
coassociative extensions satisfying the postulates of braided algebras. The
third example, describing kappa-deformed oscillators in group manifold approach
to kappa-deformed fourmomenta, is a new result.Comment: v2, 13 pages; Proc. of 2-nd Corfu School on Quantum Gravity and
Quantum Geometry, September 2009, Corfu; Gen. Rel. Grav. (2011),special
Proceedings issue; version in pres
The effects of moderately fast shellular rotation on adiabatic oscillations
We investigate adiabatic oscillations for delta Scuti star models, taking
into account a moderate rotation velocity ~100 \km/s. The resulting oscillation
frequencies include corrections for rotation up to second order in the rotation
rate including those of near degeneracy. Effects of either a uniform rotation
or a rotation profile assuming local angular momentum conservation of the form
Omega=Omega(r) on oscillation frequencies are compared. As expected, important
differences (around 3 microHz) are obtained in the and mixed mode regions.
For higher frequency p modes, differences range between 1 microHz and 3
microHz. Such differences are likely to be detectable with future space
missions such as COROT, where precisions in frequency around 0.5 microHz will
be reachable.Comment: A&A, in press (18 pag, 14 fig
Kappa-deformed oscillators, the choice of star product and free kappa-deformed quantum fields
In order to obtain free kappa-deformed quantum fields (with c-number
commutators) we proposed new concept of kappa-deformed oscillator algebra [1]
and the modification of kappa-star product [2], implementing in the product of
two quantum fields the change of standard kappa-deformed mass-shell conditions.
We recall here that the kappa-deformed oscillators recently introduced in
[3]-[5] lie on standard kappa-deformed mass-shell. Firstly, we study
kappa-deformed fields with the standard kappa-star product, what implies that
in the oscillator algebra the corresponding kappa-deformed oscillators lie on
standard kappa-deformed mass-shell. We argue that for the kappa-deformed
algebra of such field oscillators which carry fourmomenta on kappa-deformed
mass-shell it is not possible to obtain the free quantum kappa-deformed fields
with the c-number commutators. Further, we study kappa-deformed quantum fields
with the modified kappa-star product which implies the modification of
kappa-deformed mass-shell. We obtain large class of kappa-deformed statistics
depending on six arbitrary functions which provides the c-number field
commutator functions. Such general class of kappa-oscillators can be described
as the kappa-deformation of standard oscillator algebra obtained by composing
general kappa-deformed multiplication with the deformation of the flip
operator.Comment: 21 pages;v3 more clearly exposed aims and results in the paper; the
version which will appear in Journ.Phys.
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