47,138 research outputs found
Chern character for totally disconnected groups
Full text linkIn this paper we construct a bivariant Chern character for the equivariant -theory
of a totally disconnected group with values in bivariant equivariant cohomology in the sense of
Baum and Schneider. We prove in particular that the complexified left hand side of the Baum-Connes
conjecture for a totally disconnected group is isomorphic to cosheaf homology.
Moreover, it is shown that our transformation extends the Chern character defined by Baum and
Schneider for profinite groups
Symplectic Bott-Chern cohomology of solvmanifolds
No full textWe study the symplectic Bott-Chern cohomology by L.-S. Tseng and S.-T. Yau
for solvmanifolds endowed with left-invariant symplectic structures
Chern-flat and Ricci-flat invariant almost Hermitian structure
Full text linkWe study nilmanifolds endowed with a Chern connectio
Bott-Chern cohomology of solvmanifolds
No full textWe study conditions under which sub-complexes of a double complex of vector
spaces allow to compute the Bott-Chern cohomology. We are especially aimed at
studying the Bott-Chern cohomology of a special class of solvmanifolds
Quasi-Kahler Chern-flat manifolds and complex 2-step nilpotent Lie algebras
Full text linkThe study of quasi-Kaehler Chern-flat almost Hermitian manifolds is strictly related to the study of anti-bi-invariant almost complex Lie algebras. In the present paper we show that quasi-Kaehler Chern-flat almost Hermitian structures on compact manifolds are in correspondence to complex parallelisable Hermitian structures satisfying the second Gray identity. From an algebraic point of view this correspondence reads as a natural correspondence between anti-bi-invariant almost complex structures on Lie algebras to bi-invariant complex structures. Some natural algebraic problems are approached and some exotic examples are carefully describe
Chern Numbers of Uniruled Threefolds
Full text linkIn this paper we show that the Chern numbers of a smooth Mori fibre space in dimension three are bounded in terms of the underlying topological manifold. We also generalise a theorem of Cascini and the second named author on the boundedness of Chern numbers of certain threefolds to the case of negative Kodaira dimension
Resonant cavity-like modes in dielectric photonic crystals made of collections of subwavelength cylinders
No full textArtificial magnetism and anticrossing interaction in photonic crystals and split-ring structures
No full textScattering Amplitudes of Massive N=2 Gauge Theories in Three Dimensions
Full text linkWe study the scattering amplitudes of mass-deformed Chern-Simons theories and Yang-Mills-Chern-Simons theories with N=2 supersymmetry in three dimensions. In particular, we derive the on-shell supersymmetry algebras which underlie the scattering matrices of these theories. We then compute various 3 and 4-point on-shell tree-level amplitudes in these theories. For the mass-deformed Chern-Simons theory, odd-point amplitudes vanish and we find that all of the 4-point amplitudes can be encoded elegantly in superamplitudes. For the Yang-Mills-Chern-Simons theory, we obtain all of the 4-point tree-level amplitudes using a combination of perturbative techniques and algebraic constraints and we comment on difficulties related to computing amplitudes with external gauge fields using Feynman diagrams. Finally, we propose a BCFW recursion relation for mass-deformed theories in three dimensions and discuss the applicability of this proposal to mass-deformed N=2 theories
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