36,472 research outputs found
Global analysis by hidden symmetry
Hidden symmetry of a G'-space X is defined by an extension of the G'-action
on X to that of a group G containing G' as a subgroup. In this setting, we
study the relationship between the three objects:
(A) global analysis on X by using representations of G (hidden symmetry);
(B) global analysis on X by using representations of G';
(C) branching laws of representations of G when restricted to the subgroup
G'.
We explain a trick which transfers results for finite-dimensional
representations in the compact setting to those for infinite-dimensional
representations in the noncompact setting when is -spherical.
Applications to branching problems of unitary representations, and to spectral
analysis on pseudo-Riemannian locally symmetric spaces are also discussed.Comment: Special volume in honor of Roger Howe on the occasion of his 70th
birthda
Nanoscale Infrared Imaging Analysis of Carbonaceous Chondrites to Understand Organic-Mineral Interactions During Aqueous Alteration
Organic matter in carbonaceous chondrites is distributed in fine-grained matrix. To understand pre- and postaccretion history of organic matter and its association with surrounding minerals, microscopic techniques are mandatory. Infrared (IR) spectroscopy is a useful technique, but the spatial resolution of IR is limited to a few micrometers, due to the diffraction limit. In this study, we applied the high spatial resolution IR imaging method to CM2 carbonaceous chondrites Murchison and Bells, which is based on an atomic force microscopy (AFM) with its tip detecting thermal expansion of a sample resulting from absorption of infrared radiation. We confirmed that this technique permits 30 nm spatial resolution organic analysis for the meteorite samples. The IR imaging results are consistent with the previously reported association of organic matter and phyllosilicates, but our results are at much higher spatial resolution. This observation of heterogeneous distributions of the functional groups of organic matter revealed its association with minerals at 30 nm spatial resolution in meteorite samples by IR spectroscopy
Investment in Infectious Disease Control Capacity: The Case of a Potential Foot-and-Mouth Disease Outbreak in California
Health Economics and Policy,
Deadlock detection of Java Bytecode
This paper presents a technique for deadlock detection of Java programs. The
technique uses typing rules for extracting infinite-state abstract models of
the dependencies among the components of the Java intermediate language -- the
Java bytecode. Models are subsequently analysed by means of an extension of a
solver that we have defined for detecting deadlocks in process calculi. Our
technique is complemented by a prototype verifier that also covers most of the
Java features.Comment: Pre-proceedings paper presented at the 27th International Symposium
on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur,
Belgium, 10-12 October 2017 (arXiv:1708.07854
Role of anion size, magnetic moment, and disorder on the properties of the organic conductor kappa-(BETS)_2Ga_{1-x}Fe_{x}Cl_{4-y}_Br_{y}
Shubnikov-de Haas and angular dependent magnetoresistance oscillations have
been used to explore the role of anion size, magnetic moment, and disorder in
the organic conductors kappa-(BETS)_2GaBr_{4} and kappa-(BETS)_2FeCl_{2}_Br_{2}
in the isomorphic class kappa-(BETS)_2Ga_{1-x}Fe_{x}Cl_{4-y}_Br_{y}. The
results, combined with previous work, show correlations between the anion
composition (Ga_{1-x}Fe_{x}Cl_{4-y}_Br_{y}) and the superconducting transition
temperature, effective mass, Fermi surface topology, and the mean free path.Comment: 5 pages, 6 figure
Effect of pressure on the magnetic, transport, and thermal-transport properties of the electron-doped manganite CaMnSbO
We have demonstrated the effect of hydrostatic pressure on magnetic and
transport properties, and thermal transport properties in electron-doped
manganites CaMnSbO. The substitution of Sb ion for
Mn site of the parent matrix causes one-electron doping with the
chemical formula CaMnMnSbO
accompanied by a monotonous increase in unit cell volume as a function of .
Upon increasing the doping level of Sb, the magnitudes of both electrical
resistivity and negative Seebeck coefficient are suppressed at high
temperatures, indicating the electron doping. Anomalous diamagnetic behaviors
at and 0.08 are clearly observed in field cooled dc magnetization. The
effect of hydrostatic pressure on dc magnetization is in contrast to the
chemical pressure effect due to Sb doping. The dynamical effect of ac magnetic
susceptibility measurement points to the formation of the magnetically
frustrated clusters such as FM clusters embedded in canted AFM matrix.Comment: 12 pages,11 figures, 3 table
A theory of bundles over posets
In algebraic quantum field theory the spacetime manifold is replaced by a
suitable base for its topology ordered under inclusion. We explain how certain
topological invariants of the manifold can be computed in terms of the base
poset. We develop a theory of connections and curvature for bundles over posets
in search of a formulation of gauge theories in algebraic quantum field theory
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