arXiv research

Parallel transport map over reductive spaces is an affine submersion.

This paper develops a Hamiltonian reduction method for field theories over affine principal bundles.

This work extends variance reduction for path-dependent derivatives to affine stochastic volatility models.

Affine manifolds linked to integrable equations and geometric structures.

Affine deformations of cotangent groupoids

The paper classifies and determines properties of specific geometric structures.

The purpose of these survey notes is to give a presentation of a classical theorem of Nomizu that relates the invariant affine connections on reductive homogeneous spaces and nonassociative algebras.

Let M be a compact connected special affine manifold equipped with an affine Gauduchon metric. We show that a pair (E, φ), consisting of a flat vector bundle E over M and a flat nonzero section φ of E, admits a solution to the vortex equation if and only if it is polystable. To prove this, we adapt the dimensional redu…

Develops a Kaluza-Klein theory in affine spaces without metric.

Improves Marsden-Weinstein reduction theory for k-polysymplectic manifolds.

New method constructs translationally equivariant hyperbolic affine spheres.

A very important class of homogeneous Riemannian manifolds are the so-called normal homogeneous spaces, which have associated a canonical connection. In this work we obtain geometrically the (connected component of the) group of affine transformations with respect to the canonical connection for a normal homogeneous sp…

New method computes affine normal directions efficiently for sparse polynomials.

PCA adapted for curved spaces improves data analysis.

A manifold with an arbitrary affine connection is considered and the geodesic spray associated with the connection is studied in the presence of a Lie group action. In particular, results are obtained that provide insight into the structure of the reduced dynamics associated with the given invariant affine connection. …

New calculus for invariant differential operators in parabolic geometries.

We describe the structure of the Lie groups endowed with a left-invariant symplectic form, called symplectic Lie groups, in terms of semi-direct products of Lie groups, symplectic reduction and principal bundles with affine fiber. This description is particularly nice if the group is Hamiltonian, that is, if the left c…

Let $M$ be a compact connected special flat affine manifold without boundary equipped with a Gauduchon metric $g$ and a covariant constant volume form. Let $G$ be either a connected reductive complex linear algebraic group or the real locus of a split real form of a complex reductive group. We prove that a flat princip…

We give an intrinsic definition of (affine very) special real manifolds and realise any such manifold $M$ as a domain in affine space equipped with a metric which is the Hessian of a cubic polynomial. We prove that the tangent bundle $N=TM$ carries a canonical structure of (affine) special Kähler manifold. This gives a…

We give a gauge invariant characterisation of the elliptic affine sphere equation and the closely related Tzitzéica equation as reductions of real forms of $SL(3, \C)$ anti--self--dual Yang--Mills equations by two translations, or equivalently as a special case of the Hitchin equation. We use the Loftin--Yau--Zaslow co…

Develops quantum character theory for complex reductive groups.

The paper proves a Kempf-Ness theorem for non-algebraic structures.

Corrected proof of geodesics in homogeneous Finsler spaces using affine method.

Let $G$ be a connected reductive affine algebraic group defined over $\mathbb C$, and let $Γ$ be a cocompact lattice in $G$. We prove that any invariant bundle on $G/Γ$ is semistable.

The paper explores the connection between 3d gravity and Chern-Simons theory using affine group connections.

The reductive holonomy algebras for a torsion-free affine connection are analysed, with the goal of establishing which ones can correspond to a Ricci-flat connection with the same properties. Various families of holonomies are eliminated through different algebraic means, and examples are constructed (in this paper and…

New lower bounds for linear classification problems in high dimensions.

This paper discusses the exact simulation of the stock price process underlying the 3/2 model. Using a result derived by Craddock and Lennox using Lie Symmetry Analysis, we adapt the Broadie-Kaya algorithm for the simulation of affine processes to the 3/2 model. We also discuss variance reduction techniques and find th…

New construction shows DAAG/DAHA actions on congruence subgroups.

Deep learning reduces memory and computation for MRF recovery.

Introduces nonlinear splittings on fibre bundles for generalizing connections.

The paper trivializes moment maps for various geometric structures.

The anholonomic frame method is generalized for non--Riemannian gravity models defined by string corrections to the general relativity and metric-affine gravity (MAG) theories. Such spacetime configurations are modeled as metric-affine spaces provided with generic off-diagonal metrics (which can not be diagonalized by …

Reduces field theories on principal bundles by a subgroup, deriving reduced equations.

Improved non-squeezing theorem for calibrated geometries proved.

We study properly discontinuous and cocompact actions of a discrete subgroup $Γ$ of an algebraic group $G$ on a contractible algebraic manifold $X$. We suppose that this action comes from an algebraic action of $G$ on $X$ such that a maximal reductive subgroup of $G$ fixes a point. When the real rank of any simple subg…

Invariant covariant derivatives on homogeneous spaces are characterized.

We consider SU(2)-equivariant dimensional reduction of Yang-Mills theory on manifolds of the form $M\times S^3/Γ$, where $M$ is a smooth manifold and $S^3/Γ$ is a three-dimensional Sasaki-Einstein orbifold. We obtain new quiver gauge theories on $M$ whose quiver bundles are based on the affine ADE Dynkin diagram associ…

Let $G$ be a connected reductive complex affine algebraic group and $K\subset G$ a maximal compact subgroup. Let $M$ be a compact complex torus equipped with a flat Kähler structure and $(E_G ,θ)$ a polystable Higgs $G$-bundle on $M$. Take any $C^\infty$ reduction of structure group $E_K \subset E_G$ to the subgroup $K…

Let $G$ be a linear connected complex reductive Lie group. The purpose of this paper is to give explicit symplectic isomorphisms from twisted cotangent bundles of the complex generalized flag varieties, whose transition functions are given by affine transformations instead of linear transformations, onto the complex co…

In 1955, Berger \cite{Ber} gave a list of irreducible reductive representations which can occur as the holonomy of a torsion-free affine connection. This list was stated to be complete up to possibly a finite number of missing entries. In this paper, we show that there is, in fact, an infinite family of representations…

Unified geometric formulation of Maxwell-Vlasov system using presymplectic and symmetry reduction.

The paper is devoted to the local classification of generic control-affine systems on an n-dimensional manifold with scalar input for any n>3 or with two inputs for n=4 and n=5, up to state-feedback transformations, preserving the affine structure. First using the Poincare series of moduli numbers we introduce the intr…

The geometrical structure known as Tulczyjew triple has been used with success in analytical mechanics and first order field theory to describe a wide range of physical systems including Lagrangian/Hamiltonian systems with constraints and/or sources, or with singular Lagrangian. Starting from the first principles of th…

Study homotopy groups in GIT quotients using transversality methods.

Survey on real forms of a complex equation and their connection to surface theory.

Monodromy map from differential systems to character variety is generically immersive for complex $G$-representations.

This paper presents a geometric description of Lagrangian and Hamiltonian systems on Lie affgebroids subject to affine nonholonomic constraints. We define the notion of nonholonomically constrained system, and characterize regularity conditions that guarantee that the dynamics of the system can be obtained as a suitabl…