1,489 research outputs found
Recent results from the Pierre Auger Observatory
In this paper some recent results from the Pierre Auger Collaboration are
presented. These are the measurement of the energy spectrum of cosmic rays over
a wide range of energies ( to above eV), studies of the
cosmic-ray mass composition with the fluorescence and surface detector of the
Observatory, the observation of a large-scale anisotropy in the arrival
direction of cosmic rays above 8 x eV and indications of anisotropy
at intermediate angular scales above 4 x eV. The astrophysical
implications of the spectrum and composition results are also discussed.
Finally the progress of the upgrade of the Observatory, AugerPrime is
presented.Comment: 20th International Symposium on Very High Energy Cosmic Ray
Interactions (ISVHECRI 2018
From su(2) Gaudin Models to Integrable Tops
In the present paper we derive two well-known integrable cases of rigid body
dynamics (the Lagrange top and the Clebsch system) performing an algebraic
contraction on the two-body Lax matrices governing the (classical) su(2) Gaudin
models. The procedure preserves the linear r-matrix formulation of the ancestor
models. We give the Lax representation of the resulting integrable systems in
terms of su(2) Lax matrices with rational and elliptic dependencies on the
spectral parameter. We finally give some results about the many-body extensions
of the constructed systems.Comment: This is a contribution to the Vadim Kuznetsov Memorial Issue on
Integrable Systems and Related Topics, published in SIGMA (Symmetry,
Integrability and Geometry: Methods and Applications) at
http://www.emis.de/journals/SIGMA
Continuous Symmetries of the Lattice Potential KdV Equation
In this paper we present a set of results on the integration and on the
symmetries of the lattice potential Korteweg-de Vries (lpKdV) equation. Using
its associated spectral problem we construct the soliton solutions and the Lax
technique enables us to provide infinite sequences of generalized symmetries.
Finally, using a discrete symmetry of the lpKdV equation, we construct a large
class of non-autonomous generalized symmetries.Comment: 20 pages, submitted to Jour. Phys.
Spherical geometry and integrable systems
We prove that the cosine law for spherical triangles and spherical tetrahedra
defines integrable systems, both in the sense of multidimensional consistency
and in the sense of dynamical systems.Comment: 15 pages, 5 figure
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