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On Solvable Generalized Calabi-Yau Manifolds

Paolo de Bartolomeis, Adriano Tomassini (2006)

Annales de l’institut Fourier

We give an example of a compact 6-dimensional non-Kähler symplectic manifold ( M , κ ) that satisfies the Hard Lefschetz Condition. Moreover, it is showed that ( M , κ ) is a special generalized Calabi-Yau manifold.

On some properties of the upper central series in Leibniz algebras

Leonid A. Kurdachenko, Javier Otal, Igor Ya. Subbotin (2019)

Commentationes Mathematicae Universitatis Carolinae

This article discusses the Leibniz algebras whose upper hypercenter has finite codimension. It is proved that such an algebra L includes a finite dimensional ideal K such that the factor-algebra L / K is hypercentral. This result is an extension to the Leibniz algebra of the corresponding result obtained earlier for Lie algebras. It is also analogous to the corresponding results obtained for groups and modules.

On spherical nilpotent orbits and beyond

Dmitri I. Panyushev (1999)

Annales de l'institut Fourier

We continue investigations that are concerned with the complexity of nilpotent orbits in semisimple Lie algebras. We give a characterization of the spherical nilpotent orbits in terms of minimal Levi subalgebras intersecting them. This provides a kind of canonical form for such orbits. A description minimal non-spherical orbits in all simple Lie algebras is obtained. The theory developed for the adjoint representation is then extended to Vinberg’s θ -groups. This yields a description of spherical...

On tangent cones to Schubert varieties in type E

Mikhail V. Ignatyev, Aleksandr A. Shevchenko (2020)

Communications in Mathematics

We consider tangent cones to Schubert subvarieties of the flag variety G / B , where B is a Borel subgroup of a reductive complex algebraic group G of type E 6 , E 7 or E 8 . We prove that if w 1 and w 2 form a good pair of involutions in the Weyl group W of G then the tangent cones C w 1 and C w 2 to the corresponding Schubert subvarieties of G / B do not coincide as subschemes of the tangent space to G / B at the neutral point.

On the adjoint map of homotopy abelian DG-Lie algebras

Donatella Iacono, Marco Manetti (2019)

Archivum Mathematicum

We prove that a differential graded Lie algebra is homotopy abelian if its adjoint map into its cochain complex of derivations is trivial in cohomology. The converse is true for cofibrant algebras and false in general.

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