arXiv research

Defines Lewy curves in para-CR geometry and characterizes their path geometries.

Characterizes chains in 3D CR and para-CR structures.

Study para-CR structures in 5D with degenerate Levi form, revealing geometric conditions for conic graphs and Lorentzian ODEs.

We describe the automorphisms of a singular multicontact structure, that is a generalisation of the Martinet distribution. Such a structure is interpreted as a para-CR structure on a hypersurface M of a direct product space R^2 x R^2. We introduce the notion of a finite type singularity analogous to CR geometry and, al…

Almost paracontact metric manifolds are the famous examples of almost para-CR manifolds. We find necessary and suffcient conditions for such manifolds to be para-CR. Next we examine these conditions in certain subclasses of almost paracontact metric manifolds. Especially, it is shown that the normal almost paracontact …

An almost para-CR structure on a manifold $M$ is given by a distribution $HM \subset TM$ together with a field $K \in Γ({\rm End}(HM))$ of involutive endomorphisms of $HM$. If $K$ satisfies an integrability condition, then $(HM,K)$ is called a para-CR structure. The notion of maximally homogeneous para-CR structure of …

We discuss relations between the para-CR structures and differential equations (both ODEs and PDEs of finite type).

Study para-CR structures relaxing complex conjugation constraint, finding homogeneous models.

Study foundational aspects of degenerate para-CR structures and their PDE systems.

Local flatness theorem for paraquaternionic contact structures.

The paper defines $η$-normality for contact and paracontact manifolds and explores their properties.

On a $3$D manifold, a Weyl geometry consists of pairs $(g, A) =$ (metric, $1$-form) modulo gauge $\widehat{g} = {\rm e}^{2\varphi} g$, $\widehat{A} = A + {\rm d}\varphi$. In 1943, Cartan showed that every solution to the Einstein-Weyl equations $R_{(μν)} - \frac{1}{3} R g_{μν} = 0$ comes from an appropriate $3$D leaf s…

Study surfaces with constant ratio of principal curvatures in Euclidean and isotropic geometries.

It is shown that Electromagnetism creates geometry different from Riemannian geometry. General geometry including Riemannian geometry as a special case is constructed. It is proven that the most simplest special case of General Geometry is geometry underlying Electromagnetism. Action for electromagnetic field and Maxwe…

We define $(p,q)$ hermitian geometry as the target space geometry of the two dimensional $(p,q)$ supersymmetric sigma model. This includes generalised Kähler geometry for $(2,2)$, generalised hyperkähler geometry for $(4,2)$, strong Kähler with torsion geometry for $(2,1)$ and strong hyperkähler with torsion geometry f…

Non-lorentzian geometry reviewed, including Lie algebras and Klein geometries.

Simpler method derived for path geometries on surfaces, characterizing projective path geometries.

New definition of Born geometry connects to known geometries.

We give an introduction to the theory of varieties of minimal rational tangents, emphasizing its aspect as a fusion of algebraic geometry and differential geometry, more specifically, a fusion of Mori geometry of minimal rational curves and Cartan geometry of cone structures.

The paper extends group constructions to coset geometries, creating new ways to combine geometries.

Survey explores interactions between convex and complex geometry.

New symmetries found in Riemann-Cartan geometries.

Lecture notes on geodesics in differential geometry.

Lecture notes on Finslerian geometry.

Spin(7) geometry linked to multisymplectic geometry.

The extension functors between categories of Cartan geometries can be used to define different categories of Cartan geometries with additional morphisms. The Cartan geometries modeled on skeletons can be used for the description of such categories of Cartan geometries and therefore we develop the theory of Cartan geome…

A geometric transition is a continuous path of geometric structures that changes type, meaning that the model geometry, i.e. the homogeneous space on which the structures are modeled, abruptly changes. In order to rigorously study transitions, one must define a notion of geometric limit at the level of homogeneous spac…

Paper introduces a generalized Bures-Wasserstein geometry for SPD matrices.

We show that a car, viewed as a nonholonomic system, provides an example of a flat parabolic geometry of type $({\bf SO}(2,3),P_{12})$, where $P_{12}$ is a Borel parabolic subgroup in ${\bf SO}(2,3)$. We discuss the relations of this geometry of a car with the geometry of circles in the plane (a low dimensional Lie sph…

The study sets limits on the complexity of Klein geometries.

Surveying probabilistic real algebraic geometry.

Develops Weyl structures for path geometries, simplifying their study.

Ray-marching method visualizes 8 Thurston geometries in real-time.

The paper extends Ruh-Vilms theorem to hypersurfaces in Weitzenböck geometry.

Paper develops formulas and theorems in Hermitian geometry.

Introduces a new geometry based on difference angles, showing unique properties.

We introduce the notion of manifolds of amalgamation geometry and its generalization, split geometry. We show that the limit set of any surface group of split geometry is locally connected, by constructing a natural Cannon-Thurston map.

KT-geometry is the geometry of a Hermitian connection whose torsion is a 3-form. HKT-geometry is the geometry of a hyper-Hermitian connection whose torsion is a 3-form. We identify non-trivial conditions for a reduction theory for these types of geometry.

We classify the 5-dimensional homogeneous geometries in the sense of Thurston. The present paper (part 3 of 3) classifies those in which the linear isotropy representation is nontrivial but reducible. Most of the resulting geometries are products. Some interesting examples include a countably infinite family of inequiv…

New framework for noncommutative Carrollian geometry using Lie-Rinehart pairs.

Authors discuss complex and non-Archimedean geometry, proving a conjecture.

The target space geometry of abelian vector multiplets in ${\cal N}= 2$ theories in four and five space-time dimensions is called special geometry. It can be elegantly formulated in terms of Hessian geometry. In this review, we introduce Hessian geometry, focussing on aspects that are relevant for the special geometrie…

Quantum field theory connects Riemannian geometry to quantum fluctuations.

New geometry based on Siegel upper half-space with volume formula.

Develops a new algebraic framework for differential geometry of infinite dimensional spaces.

Study of Teichmüller space geometry using infinitesimal and global methods.

The study identifies two sources of invariants in 2--nondegenerate CR geometries.

We will survey some aspects of the smooth topology, algebraic geometry, symplectic geometry and contact geometry of anti-canonical pairs in complex dimension two.