Solutions of the tt*-Toda Equations and Quantum Cohomology of Flag Manifolds

De Rham $2$-cohomology of real flag manifolds

Let $\mathbb{F}_{Θ}=G/P_{Θ}$ be a flag manifold associated to a non-compact real simple Lie group $G$ and the parabolic subgroup $% P_{Θ}$. This is a closed subgroup of $G$ determined by a subset $% Θ$ of simple restricted roots of $\mathfrak{g}=Lie(G)$. This paper computes the second de Rham cohomology group of $\mathbb{F}_Θ$. We prove that it zero in general, with some rare exceptions. When it is non-zero, we give a basis of $H^2(\mathbb{F}_Θ,\mathbb{R})$ through the Weil construction of closed 2-forms as characteristic classes of principal fiber bundles. The starting point is the computatio…

Equivariant cohomology of real flag manifolds

Let $P=G/K$ be a semisimple non-compact Riemannian symmetric space, where $G=I_0(P)$ and $K=G_p$ is the stabilizer of $p\in P$. Let $X$ be an orbit of the (isotropy) representation of $K$ on $T_p(P)$ ($X$ is called a real flag manifold). Let $K_0\subset K$ be the stabilizer of a maximal flat, totally geodesic submanifold of $P$ which contains $p$. We show that if all the simple root multiplicities of $G/K$ are at least 2 then $K_0$ is connected and the action of $K_0$ on $X$ is equivariantly formal. In the case when the multiplicities are equal and at least 2, we will give a purely geometric p…

极小凝聚同调群与仿射旗流形的余切丛

Intersection cohomology groups of instanton moduli spaces and cotangent bundles of affine flag varieties

研究极小凝聚同调群与仿射旗流形余切丛的等效特征，通过猜想的几何Satake对应关系在Kac-Moody设定中进行表征，并在仿射类型A中给出了证明框架。

An atlas adapted to the Toda flow

We introduce an atlas adapted to the Toda flow on the manifold of full flags of any non-compact real semisimple Lie algebra, and on its Hessenberg-type submanifolds. In our local coordinates the Toda flow becomes linear. We use these new coordinates to show that the Toda flow on the manifold of full flags is Morse-Smale, which generalizes the main result of \cite{CSS1} to arbitrary non-compact real semisimple Lie algebras. As a byproduct we describe new features of classical constructions in matrix theory.

Killing fields and Conservation Laws for rank-1 Toda field equations

We present a connection between the Killing fields that arise in the loop-group approach to integrable systems and conservation laws viewed as elements of the characteristic cohomology. We use the connection to generate the complete set of conservation laws (as elements of the characteristic cohomology) for the Tzitzeica equation, completing the work in Fox and Goertsches (2011). We define a notion of finite-type for integral manifolds of exterior differential systems directly in terms of conservation laws that generalizes the definition of Pinkall-Sterling (1989). The definition applies to an…

Pseudo-Kaehler Quantization on Flag Manifolds

A unified approach to geometric, symbol and deformation quantizations on a generalized flag manifold endowed with an invariant pseudo-Kaehler structure is proposed. The Hilbert space of states is realized via the Bott-Borel-Weil theorem in the sheaf cohomology of the geometric quantization line bundle. The corresponding deformation quantization is a quantization with separation of variables. In particular cases we arrive at Berezin's quantization via covariant and contravariant symbols.

紧埃尔米特局部对称空间上旗丛的上同调

Cohomology of flag bundles over compact Hermitian locally symmetric spaces

本文研究紧埃尔米特局部对称空间上旗丛的上同调，刻画了对应商空间的上同调、Picard群，并推广了单群情形下$p=0,1$时上同调消失的已有结果。

Differential Geometry of Toda Systems

In the present paper we give a differential geometry formulation of the basic dynamical principle of the group--algebraic approach \cite{LeS92} --- the grading condition --- in terms of some holomorphic distributions on flag manifolds associated with the parabolic subgroups of a complex Lie group; and a derivation of the corresponding nonlinear integrable systems, and their general solutions. Moreover, the reality condition for these solutions is introduced. For the case of the simple Lie groups endowed with the canonical gradation, when the systems in question are reduced to the abelian Toda …

Toda field theories and integral curves of standard differential systems

This paper establishes three relations between the Toda field theory associated to a simple Lie algebra and the integral curves of the standard differential system on the corresponding complete flag variety. The motivation comes from the viewpoint on the Toda field theories as Darboux integrable differential systems as developed in \cite{AFV}. First, we establish an isomorphism concerning regular functions on the jet space and on the unipotent subgroup in the setting of a simple Lie group. Using this result, we then show that in the sense of differential systems, after restricting one independ…

广义格拉斯曼流形的Hochschild上同调

Hochschild cohomology of generalised Grassmannians

本文计算广义格拉斯曼流形的Hochschild上同调的HKR分解，证明其在（余）极小型和（余）伴随型情形集中于整体截面，并给出Gerstenhaber代数结构的显式部分描述。