2,484 research outputs found
Universality of Low-Energy Scattering in 2+1 Dimensions: The Non Symmetric Case
For a very large class of potentials, , , we
prove the universality of the low energy scattering amplitude, . The result is . The
only exceptions occur if happens to have a zero energy bound state. Our new
result includes as a special subclass the case of rotationally symmetric
potentials, .Comment: 65 pages, Latex, significant changes, new sections and appendice
On the Nonlocal Equations and Nonlocal Charges Associated with the Harry Dym Hierarchy
A large class of nonlocal equations and nonlocal charges for the Harry Dym
hierarchy is exhibited. They are obtained from nonlocal Casimirs associated
with its bi-Hamiltonian structure. The Lax representation for some of these
equations is also given.Comment: to appear in Journal of Mathematical Physics, 17 pages, Late
Deformed Harry Dym and Hunter-Zheng Equations
We study the deformed Harry Dym and Hunter-Zheng equations with two arbitrary
deformation parameters. These reduce to various other known models in
appropriate limits. We show that both these systems are bi-Hamiltonian with the
same Hamiltonian structures. They are integrable and belong to the same
hierarchy corresponding to positive and negative flows. We present the Lax pair
description for both the systems and construct the conserved charges of
negative order from the Lax operator. For the deformed Harry Dym equation, we
construct the non-standard Lax representation for two special classes of values
of the deformation parameters. In general, we argue that a non-standard
description will involve a pseudo-differential operator of infinite order.Comment: Latex file, 15 page
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Living in Plurilingual Spaces: Self-Study, Critical Friendship, and the Plurality of Publics
In this article we engage in collaborative self-study through a critical friendship that is specifically designed to evoke our personal histories in relation to how we approach our practices as teacher educators. In particular, we focus on understanding the conceptual origins of our pedagogies of teacher education and how our identities as teacher educators were shaped, and continue to be shaped, by colleagues, teacher candidates, and by the process of self-study itself. We argue that the multiple studies that are available to any self-study research program creates a plurality of publics in which we identify, and are identified, in particular ways by particular members of the teacher education community. One significant avenue for our developing line of work concerns the ways in which our shared bilingualism plays out during our critical friendship, and how the use of multiple languages helps us to reframe our identities as teacher educators, particularly whilst engaged in translanguaging practices
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