326,759 research outputs found
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
Bott–Chern cohomology and q-complete domains
No full textIn studying the Bott–Chern and Aeppli cohomologies for q-complete manifolds, we introduce the class of cohomologically Bott–Chern q-complete manifolds
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
Chern-flat and Ricci-flat invariant almost Hermitian structure
No full textWe study nilmanifolds endowed with a Chern connectio
On the -Lemma and Bott-Chern cohomology
No full textOn a compact complex manifold X, we prove a Frölicher-type inequality for Bott-Chern cohomology and we show that the equality holds if and only if X satisfies the ∂∂− -Lemma
Quasi-Kahler Chern-flat manifolds and complex 2-step nilpotent Lie algebras
No full textThe 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
Scattering Amplitudes of Massive N=2 Gauge Theories in Three Dimensions
No full textWe 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
Chern Numbers of Uniruled Threefolds
No full textIn 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
Chern classes for coherent sheaves
No full textWe present in this paper a construction of Chern classes
for a coherent sheaf S on a complex manifold X. In fact we
construct classes Cp(S) in H2p(X, C), depending only on the
smooth equivalence class of the sheaf S. and analytic classes
CAp(S) in Hp(X, Ωp) (Ωp denotes the sheaf of germs of holomorphic
p-forms on X). We show that these invariants extend the classical
and Atiyah constructions for locally free sheaves, and that the
analytic class CAp(S) is the 'leading term' of type (p, p) in the
expansion by type of Cp(S). In the case of a compact manifold,
we are able to show that the classes Cp(S) correspond (up to a
constant factor) with those defined by Atiyah and Hirzebruch in
[2]. Thus in particular the Cp(S) are integral cohomology classes
Everyday stuff--Cover
No full textComic book in single section sewn into handmade paper covers. Title and author printed on front coverUNL SPEC copy--Limited ed., no. 21 of 50 copies, signed by the autho
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