68 research outputs found

    Potentials with Two Shifted Sets of Equally Spaced Eigenvalues and Their Calogero Spectrum

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    Motivated by the concept of shape invariance in supersymmetric quantum mechanics, we obtain potentials whose spectrum consists of two shifted sets of equally spaced energy levels. These potentials are similar to the Calogero-Sutherland model except the singular term αx−2\alpha x^{-2} always falls in the transition region −1/4<α<3/4-1/4 < \alpha < 3/4 and there is a delta-function singularity at x=0.Comment: Latex, 12 pages, Figures available from Authors, To appear in Physics Letters A. Please send requests for figures to [email protected] or [email protected]

    Galileo\u27s Contribution to Mechanics

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    Asim Gangopadhyaya writes about Galileo\u27s contributions to mechanics and physics in this chapter in Where Have All the Heavens Gone? Galileo\u27s Letter to the Grand Duchess Christina edited by John P. McCarthy and Edmondo F. Lupieri

    The motion of two identical masses connected by an ideal string symmetrically placed over a corner

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    We introduce a novel, two-mass system that slides up an inclined plane while its center of mass moves down. The system consists of two identical masses connected by an ideal string symmetrically placed over a corner-shaped support. This system is similar to a double-cone that rolls up an inclined set of V-shaped rails. We find the double-cone's motion easy to demonstrate but difficult to analyze. Our example here is more straightforward to follow, and the experimental observations are in good agreement with the theoretical predictions.Comment: 10 pages, 7 figures; Accepted for publication in American Journal of Physic

    Unintended consequences of imprecise Notation -- an example from mechanics

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    We present a conundrum that results from the imprecise use of notation for partial derivatives. Taking an example from mechanics, we show that lack of proper care in representing partial derivatives in Lagrangian and Hamiltonian formulations paradoxically leads to two different values for the time derivative of the canonical momentum. This problem also exists in other areas of physics, such as thermodynamics

    Barn and Pole paradox: revisited

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    We present two different paradoxes related to the length contraction in special relativity and explain their resolution.Comment: 7 pages, 6 figures. To appear in Physics Education, IOP Scienc

    Non-Central Potentials and Spherical Harmonics Using Supersymmetry and Shape Invariance

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    It is shown that the operator methods of supersymmetric quantum mechanics and the concept of shape invariance can profitably be used to derive properties of spherical harmonics in a simple way. The same operator techniques can also be applied to several problems with non-central vector and scalar potentials. As examples, we analyze the bound state spectra of an electron in a Coulomb plus an Aharonov-Bohm field and/or in the magnetic field of a Dirac monopole.Comment: Latex, 12 pages. To appear in American Journal of Physic

    Methods for Generating Quasi-Exactly Solvable Potentials

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    We describe three different methods for generating quasi-exactly solvable potentials, for which a finite number of eigenstates are analytically known. The three methods are respectively based on (i) a polynomial ansatz for wave functions; (ii) point canonical transformations; (iii) supersymmetric quantum mechanics. The methods are rather general and give considerably richer results than those available in the current literature.Comment: 12 pages, LaTe

    Superspace Ward Identities in Supersymmetric Gauge Theories

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    In superspace formulation of supersymmetric gauge theories, gauge invariance requires an infinite set of identities between the infinite set of renormalization constants. Using Ward identities in superspace, the same is derived. These identities at one loop level are also demonstrated