scholarly journals SYMPLECTIC CONNECTIONS

2006 ◽  
Vol 03 (03) ◽  
pp. 375-420 ◽  
Author(s):  
PIERRE BIELIAVSKY ◽  
MICHEL CAHEN ◽  
SIMONE GUTT ◽  
JOHN RAWNSLEY ◽  
LORENZ SCHWACHHÖFER

This article is an overview of the results obtained in recent years on symplectic connections. We present what is known about preferred connections (critical points of a variational principle). The class of Ricci-type connections (for which the curvature is entirely determined by the Ricci tensor) is described in detail, as well as its far-reaching generalization to special connections. A twistorial construction shows a relation between Ricci-type connections and complex geometry. We give a construction of Ricci-flat symplectic connections. We end up by presenting, through an explicit example, an approach to non-commutative symplectic symmetric spaces.

2015 ◽  
Vol 6 (4) ◽  
pp. 107-113
Author(s):  
C. Bosch ◽  
C.L. García ◽  
F. Garibay-Bonales ◽  
C. Gómez-Wulschner ◽  
R. Vera

2014 ◽  
Vol 57 (3) ◽  
pp. 643-651
Author(s):  
TETSUYA TANIGUCHI ◽  
SEIICHI UDAGAWA

AbstractGiven the pair (P, η) of (0,2) tensors, where η defines a volume element, we consider a new variational problem varying η only. We then have Einstein metrics and slant immersions as critical points of the 1st variation. We may characterize Ricci flat metrics and Lagrangian submanifolds as stable critical points of our variational problem.


1997 ◽  
Vol 17 (5) ◽  
pp. 1131-1135 ◽  
Author(s):  
GERHARD KNIEPER

In this paper we study a new functional on the space of metrics with negative curvature on a compact manifold. It is a linear combination of Liouville entropy and total scalar curvature. Locally symmetric spaces are critical points of this functional. We provide an explicit formula for its second derivative at metrics of constant negative curvature. In particular, this shows that a metric of constant curvature is a local maximum.


2003 ◽  
Vol 2003 (13) ◽  
pp. 757-768 ◽  
Author(s):  
Mabel Cuesta

We prove two minimax principles to find almost critical points ofC1functionals restricted to globally definedC1manifolds of codimension1. The proof of the theorems relies on Ekeland variational principle.


2003 ◽  
Vol 46 (3) ◽  
pp. 747-766 ◽  
Author(s):  
Charles Boubel

AbstractA symplectic connection on a symplectic manifold, unlike the Levi-Civita connection on a Riemannian manifold, is not unique. However, some spaces admit a canonical connection (symmetric symplectic spaces, Kähler manifolds, etc.); besides, some ‘preferred’ symplectic connections can be defined in some situations. These facts motivate a study of the symplectic connections, inducing a parallel Ricci tensor. This paper gives the possible forms of the Ricci curvature on such manifolds and gives a decomposition theorem (linked with the holonomy decomposition) for them.AMS 2000 Mathematics subject classification: Primary 53B05; 53B30; 53B35; 53C25; 53C55


2006 ◽  
Vol 21 (25) ◽  
pp. 5043-5097 ◽  
Author(s):  
STEFANO BELLUCCI ◽  
SERGIO FERRARA ◽  
MURAT GÜNAYDIN ◽  
ALESSIO MARRANI

We study the critical points of the black hole scalar potential V BH in N = 2, d = 4 supergravity coupled to nV vector multiplets, in an asymptotically flat extremal black hole background described by a 2(nV+1)-dimensional dyonic charge vector and (complex) scalar fields which are coordinates of a special Kähler manifold. For the case of homogeneous symmetric spaces, we find three general classes of regular attractor solutions with nonvanishing Bekenstein–Hawking entropy. They correspond to three (inequivalent) classes of orbits of the charge vector, which is in a 2(nV+1)-dimensional representation RV of the U-duality group. Such orbits are nondegenerate, namely they have nonvanishing quartic invariant (for rank-3 spaces). Other than the ½-BPS one, there are two other distinct non-BPS classes of charge orbits, one of which has vanishing central charge. The three species of solutions to the N = 2 extremal black hole attractor equations give rise to different mass spectra of the scalar fluctuations, whose pattern can be inferred by using invariance properties of the critical points of V BH and some group theoretical considerations on homogeneous symmetric special Kähler geometry.


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