Search arXiv⌕ Search

arXiv · 1604.00146

Pre-symplectic algebroids and their applications

Abstract

In this paper, we introduce the notion of a pre-symplectic algebroid, and show that there is a one-to-one correspondence between pre-symplectic algebroids and symplectic Lie algebroids. This result is the geometric generalization of the relation between left-symmetric algebras and symplectic (Frobenius) Lie algebras. Although pre-symplectic algebroids are not left-symmetric algebroids, they still can be viewed as the underlying structures of symplectic Lie algebroids. %We study three classes of pre-symplectic algebroids in detail. Then we study exact pre-symplectic algebroids and show that they are classified by the third cohomology group of a left-symmetric algebroid. Finally, we study para-complex pre-symplectic algebroids. Associated to a para-complex pre-symplectic algebroid, there is a pseudo-Riemannian Lie algebroid. The multiplication in a para-complex pre-symplectic algebroid characterizes the restriction to the Lagrangian subalgebroids of the Levi-Civita connection in the corresponding pseudo-Riemannian Lie algebroid.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jiefeng Liu, Yunhe Sheng, Chengming Bai. 2017-01-11. Pre-symplectic algebroids and their applications. https://doi.org/10.1007/s11005-017-0973-8

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

The signature of geometrically decomposable aspherical 4-manifolds

We construct examples of geometrically decomposable aspherical 4-manifolds with non-zero signature. We show that all such 4-manifolds satisfy the inequality (of Bogomolov--Miyaoka--Yau type) $χ\geq 3|σ|$. We also construct examples attaining the equality that are non-geometric and have non-zero signature. Finally, we prove that for higher graph 4-manifolds, with complex-hyperbolic vertices, the strict inequality always holds. Moreover, we construct infinitely many examples of higher graph 4-manifolds with non-zero signature and prove that the inequality is strict and sharp in this class.

math.DG↗

Chen-Ricci and Hineva Inequalities For Riemannian Submersions and Riemannian Maps With Applications

The Chen--Ricci inequality provides a sharp upper estimate for the Ricci curvature in terms of the ambient curvature and the squared mean curvature, whereas the Hineva inequality gives a complementary lower estimate. Although Chen--Ricci inequalities have been investigated for Riemannian submersions and Riemannian maps, the corresponding Hineva inequalities have not yet been systematically studied in these settings. In this paper, we fill this gap by establishing sharp Hineva inequalities for Riemannian submersions and Riemannian maps. We also provide alternative and direct proofs of the Chen--Ricci inequalities by working directly with the Ricci curvature, rather than proceeding through scalar-curvature identities and optimization arguments. For Riemannian submersions, we obtain sharp upper and lower estimates along the vertical and mixed distributions, while for Riemannian maps we obtain corresponding estimates along the range distribution. The equality cases are completely characterized, and the simultaneous equality of the Chen--Ricci and Hineva inequalities is investigated. As applications, we obtain the corresponding two-sided Ricci-curvature estimates for Riemannian submersions from real and complex space forms and for Riemannian maps into real and complex space forms. Several examples are presented to demonstrate the sharpness of the obtained inequalities.

math.DG↗

Extrinsic characterizations of biconservative surfaces in the $4$-dimensional hyperbolic space

Biconservative submanifolds arise as a natural relaxation of the biharmonic condition and play an important role in the submanifold theory. In this paper, we study non-CMC biconservative surfaces with parallel normalized mean curvature vector field (PNMC surfaces) in the four-dimensional hyperbolic space $\mathbb{H}^4$, for which we consider the hyperboloid model. We provide a local extrinsic description of such surfaces, showing that they are generated by a directrix curve lying in a totally geodesic hypersurface $\mathbb{H}^3$ of $\mathbb{H}^4$, through a certain normal flow. This extrinsic classification of non-CMC, PNMC biconservative surfaces in $\mathbb{H}^4$ splits naturally into three cases according to the type of a certain vector field, which can be non-zero null, spacelike or timelike. We also prove that these surfaces are invariant under the action of a parabolic, elliptic, and hyperbolic one-parameter group of isometries of $\mathbb{H}^4$, respectively. Moreover, their full groups of ambient isometries preserving the surfaces are determined. Together with the previous results, the classification of non-CMC, PNMC surfaces in four-dimensional space forms is now complete, from both intrinsic and extrinsic points of view.

math.DG↗