7,335 research outputs found

    On the modification of Hamiltonians' spectrum in gravitational quantum mechanics

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    Different candidates of Quantum Gravity such as String Theory, Doubly Special Relativity, Loop Quantum Gravity and black hole physics all predict the existence of a minimum observable length or a maximum observable momentum which modifies the Heisenberg uncertainty principle. This modified version is usually called the Generalized (Gravitational) Uncertainty Principle (GUP) and changes all Hamiltonians in quantum mechanics. In this Letter, we use a recently proposed GUP which is consistent with String Theory, Doubly Special Relativity and black hole physics and predicts both a minimum measurable length and a maximum measurable momentum. This form of GUP results in two additional terms in any quantum mechanical Hamiltonian, proportional to αp3\alpha p^3 and α2p4\alpha^2 p^4, respectively, where α∌1/MPlc\alpha \sim 1/M_{Pl}c is the GUP parameter. By considering both terms as perturbations, we study two quantum mechanical systems in the framework of the proposed GUP: a particle in a box and a simple harmonic oscillator. We demonstrate that, for the general polynomial potentials, the corrections to the highly excited eigenenergies are proportional to their square values. We show that this result is exact for the case of a particle in a box.Comment: 11 pages, to appear in Europhysics Letter

    Center Domains and their Phenomenological Consequences

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    We argue that the domain structure of deconfined QCD matter, which can be inferred from the properties of the Polyakov loop, can simultaneously explain the two most prominent experimentally verified features of the quark-gluon plasma, namely its large opacity as well as its near ideal fluid properties

    One dimensional Coulomb-like problem in deformed space with minimal length

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    Spectrum and eigenfunctions in the momentum representation for 1D Coulomb potential with deformed Heisenberg algebra leading to minimal length are found exactly. It is shown that correction due to the deformation is proportional to square root of the deformation parameter. We obtain the same spectrum using Bohr-Sommerfeld quantization condition.Comment: 11 pages, typos corrected, references adde

    Hydrogen atom as an eigenvalue problem in 3D spaces of constant curvature and minimal length

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    An old result of A.F. Stevenson [Phys. Rev.} 59, 842 (1941)] concerning the Kepler-Coulomb quantum problem on the three-dimensional (3D) hypersphere is considered from the perspective of the radial Schr\"odinger equations on 3D spaces of any (either positive, zero or negative) constant curvature. Further to Stevenson, we show in detail how to get the hypergeometric wavefunction for the hydrogen atom case. Finally, we make a comparison between the ``space curvature" effects and minimal length effects for the hydrogen spectrumComment: 6 pages, v

    On Dirac theory in the space with deformed Heisenberg algebra. Exact solutions

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    The Dirac equation has been studied in which the Dirac matrices \hat{\boldmath\alpha}, \hat\beta have space factors, respectively ff and f1f_1, dependent on the particle's space coordinates. The ff function deforms Heisenberg algebra for the coordinates and momenta operators, the function f1f_1 being treated as a dependence of the particle mass on its position. The properties of these functions in the transition to the Schr\"odinger equation are discussed. The exact solution of the Dirac equation for the particle motion in the Coulomnb field with a linear dependence of the ff function on the distance rr to the force centre and the inverse dependence on rr for the f1f_1 function has been found.Comment: 13 page

    Deformed Heisenberg algebra and minimal length

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    A one-dimensional deformed Heisenberg algebra [X,P]=if(P)[X,P]=if(P) is studied. We answer the question: For what function of deformation f(P)f(P) there exists a nonzero minimal uncertainty in position (minimal length). We also find an explicit expression for the minimal length in the case of arbitrary function of deformation.Comment: to be published in JP

    Effect of the Generalized Uncertainty Principle on Post-Inflation Preheating

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    We examine effects of the Generalized Uncertainty Principle, predicted by various theories of quantum gravity to replace the Heisenberg's uncertainty principle near the Planck scale, on post inflation preheating in cosmology, and show that it can predict either an increase or a decrease in parametric resonance and a corresponding change in particle production. Possible implications are considered.Comment: v1: 9 pages, revtex4, no figures, accepted for publication in JCAP; v2: one reference added and various cosmetic (but no physics) changes to match published versio

    Reducing the oral quinine-quinidine-cinchonin (Quinimax) treatment of uncomplicated malaria to three days does not increase the recurrence of attacks among children living in a highly endemic area of Senegal

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    A 3 d shortened course of the quinine-quinidine-cinchonin association Quinimax (trademark) was compared to the usual 7 d regimen for routinely treating 462 acute uncomplicated #Plasmodium falciparummalariaattacksin72childrenundertheageof10yearsinDielmo,aholoendemicvillageinSenegal.25mg/kgQuinimax(trademark)saltdaily,givenin3equaldoses,improvedclinicalstatusin99.6 malaria attacks in 72 children under the age of 10 years in Dielmo, a holoendemic village in Senegal. 25 mg/kg Quinimax (trademark) salt daily, given in 3 equal doses, improved clinical status in 99.6% of the patients receiving the course and in all of those treated for 7 d. Even if the 3 d course did not systematically eliminate parasitaemia, reducing oral Quinimax (trademark) treatment of uncomplicated malaria from 7 to 3 d did not increase the recurrence of attacks, even among the youngest children. Both the quinine sensitivity of the Senegalese strains of #P. falciparum and the partial acquired immunity of the children were probably responsible for the absence of any difference between the courses. Oral Quinimax (trademark) for 3 d is a possible alternative regimen to chloroquine and sulfadoxine-pyrimethamine for treating uncomplicated malaria in highly endemic areas of Africa where clinical resistance to these drugs exists. (Résumé d'auteur
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