3,766 research outputs found

    Decomposition of symmetric tensor fields in the presence of a flat contact projective structure

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    Let MM be an odd-dimensional Euclidean space endowed with a contact 1-form α\alpha. We investigate the space of symmetric contravariant tensor fields on MM as a module over the Lie algebra of contact vector fields, i.e. over the Lie subalgebra made up by those vector fields that preserve the contact structure. If we consider symmetric tensor fields with coefficients in tensor densities, the vertical cotangent lift of contact form α\alpha is a contact invariant operator. We also extend the classical contact Hamiltonian to the space of symmetric density valued tensor fields. This generalized Hamiltonian operator on the symbol space is invariant with respect to the action of the projective contact algebra sp(2n+2)sp(2n+2). The preceding invariant operators lead to a decomposition of the symbol space (expect for some critical density weights), which generalizes a splitting proposed by V. Ovsienko

    On sl(2)-equivariant quantizations

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    By computing certain cohomology of Vect(M) of smooth vector fields we prove that on 1-dimensional manifolds M there is no quantization map intertwining the action of non-projective embeddings of the Lie algebra sl(2) into the Lie algebra Vect(M). Contrariwise, for projective embeddings sl(2)-equivariant quantization exists.Comment: 09 pages, LaTeX2e, no figures; to appear in Journal of Nonlinear Mathematical Physic

    Novel inferences of ionisation & recombination for particle/power balance during detached discharges using deuterium Balmer line spectroscopy

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    The physics of divertor detachment is determined by divertor power, particle and momentum balance. This work provides a novel analysis technique of the Balmer line series to obtain a full particle/power balance measurement of the divertor. This supplies new information to understand what controls the divertor target ion flux during detachment. Atomic deuterium excitation emission is separated from recombination quantitatively using Balmer series line ratios. This enables analysing those two components individually, providing ionisation/recombination source/sinks and hydrogenic power loss measurements. Probabilistic Monte Carlo techniques were employed to obtain full error propagation - eventually resulting in probability density functions for each output variable. Both local and overall particle and power balance in the divertor are then obtained. These techniques and their assumptions have been verified by comparing the analysed synthetic diagnostic 'measurements' obtained from SOLPS simulation results for the same discharge. Power/particle balance measurements have been obtained during attached and detached conditions on the TCV tokamak.Comment: The analysis results of this paper were formerly in arXiv:1810.0496

    Non-commuting coordinates, exotic particles, & anomalous anyons in the Hall effect

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    Our previous ``exotic'' particle, together with the more recent anomalous anyon model (which has arbitrary gyromagnetic factor gg) are reviewed. The non-relativistic limit of the anyon generalizes the exotic particle which has g=0g=0 to any gg.When put into planar electric and magnetic fields, the Hall effect becomes mandatory for all g2g\neq2, when the field takes some critical value.Comment: A new reference added. Talk given by P. Horvathy at the International Workshop "Nonlinear Physics: Theory and Experiment. III. July'04, Gallipoli (Lecce, Italy). To be published in Theor. Math. Phys. Latex 9 pages, no figure

    Transverse Shifts in Paraxial Spinoptics

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    The paraxial approximation of a classical spinning photon is shown to yield an "exotic particle" in the plane transverse to the propagation. The previously proposed and observed position shift between media with different refractive indices is modified when the interface is curved, and there also appears a novel, momentum [direction] shift. The laws of thin lenses are modified accordingly.Comment: 3 pages, no figures. One detail clarified, some misprints corrected and references adde

    Cohomology of groups of diffeomorphims related to the modules of differential operators on a smooth manifold

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    Let MM be a manifold and TMT^*M be the cotangent bundle. We introduce a 1-cocycle on the group of diffeomorphisms of MM with values in the space of linear differential operators acting on C(TM).C^{\infty} (T^*M). When MM is the nn-dimensional sphere, SnS^n, we use this 1-cocycle to compute the first-cohomology group of the group of diffeomorphisms of SnS^n, with coefficients in the space of linear differential operators acting on contravariant tensor fields.Comment: arxiv version is already officia

    Twist Deformation of Rotationally Invariant Quantum Mechanics

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    Non-commutative Quantum Mechanics in 3D is investigated in the framework of the abelian Drinfeld twist which deforms a given Hopf algebra while preserving its Hopf algebra structure. Composite operators (of coordinates and momenta) entering the Hamiltonian have to be reinterpreted as primitive elements of a dynamical Lie algebra which could be either finite (for the harmonic oscillator) or infinite (in the general case). The deformed brackets of the deformed angular momenta close the so(3) algebra. On the other hand, undeformed rotationally invariant operators can become, under deformation, anomalous (the anomaly vanishes when the deformation parameter goes to zero). The deformed operators, Taylor-expanded in the deformation parameter, can be selected to minimize the anomaly. We present the deformations (and their anomalies) of undeformed rotationally-invariant operators corresponding to the harmonic oscillator (quadratic potential), the anharmonic oscillator (quartic potential) and the Coulomb potential.Comment: 20 page

    Generalized Massive Gravity and Galilean Conformal Algebra in two dimensions

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    Galilean conformal algebra (GCA) in two dimensions arises as contraction of two copies of the centrally extended Virasoro algebra (tt,xϵxt\rightarrow t, x\rightarrow\epsilon x with ϵ0\epsilon\rightarrow 0). The central charges of GCA can be expressed in term of Virasoro central charges. For finite and non-zero GCA central charges, the Virasoro central charges must behave as asymmetric form O(1)±O(1ϵ)O(1)\pm O(\frac{1}{\epsilon}). We propose that, the bulk description for 2d GCA with asymmetric central charges is given by general massive gravity (GMG) in three dimensions. It can be seen that, if the gravitational Chern-Simons coupling 1μ\frac{1}{\mu} behaves as of order O(1ϵ\frac{1}{\epsilon}) or (μϵμ\mu\rightarrow\epsilon\mu), the central charges of GMG have the above ϵ\epsilon dependence. So, in non-relativistic scaling limit μϵμ\mu\rightarrow\epsilon\mu, we calculated GCA parameters and finite entropy in term of gravity parameters mass and angular momentum of GMG.Comment: 9 page

    On the Schrödinger-Newton equation and its symmetries: a geometric view

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    LaTeX 29 pages; minor correctionsInternational audienceThe \SN (SN) equation is recast on purely geometrical grounds, namely in terms of Bargmann structures over (\d+1)-dimensional Newton-Cartan (NC) spacetimes. Its maximal group of invariance, which we call the SN group, is determined as the group of conformal Bargmann automorphisms that preserve the coupled Schr\"odinger and NC gravitational field equations. Canonical unitary representations of the SN group are worked out, helping us recover, in particular, a very specific occurrence of dilations with dynamical exponent z=(\d+2)/3

    Vortex solutions in axial or chiral coupled non-relativistic spinor- Chern-Simons theory

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    The interaction of a spin 1/2 particle (described by the non-relativistic "Dirac" equation of L\'evy-Leblond) with Chern-Simons gauge fields is studied. It is shown, that similarly to the four dimensional spinor models, there is a consistent possibility of coupling them also by axial or chiral type currents. Static self dual vortex solutions together with a vortex-lattice are found with the new couplings.Comment: Plain TEX, 10 page
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