arXiv research

We study decompositions of complex hyperbolic isometries as products of involutions. We show that PU(2,1) has involution length 4 and commutator length 1, and that for all $n \geqslant 3$ PU($n$,1) has involution length at most 8.

Study geodesic diameter on surfaces with special symmetry.

A $k$-reflection of the $n$-dimensional complex hyperbolic space ${\rm H}_{\C}^n$ is an element in ${\rm U}(n,1)$ with negative type eigenvalue $λ$, $|λ|=1$, of multiplicity $k+1$ and positive type eigenvalue $1$ of multiplicity $n-k$. We prove that a holomorphic isometry of ${\rm H}_{\C}^n$ is a product of at most fou…

Every element of PU(2,1) can be decomposed into at most 4 special elliptic isometries.

We study complex Lagrangian submanifolds of a compact hyper-Kähler manifold and prove two results: (a) that an involution of a hyper-Kähler manifold which is antiholomorphic with respect to one complex structure and which acts non-trivially on the corresponding symplectic form always has a fixed point locus which is co…

A new algorithm simplifies number theory and geometry problems.

Unified construction of compactifications using Grassmannian geometry.

In this paper we develop a complete theory of factorization for isometries of hyperbolic 4-space. Of special interest is the case where a pair of isometries is linked, that is, when a pair of isometries can be expressed each as compositions of two involutions, one of which is common to both isometries. Here we develop …

We present a new description of the genus 3 Arnoux--Yoccoz translation surface in terms of its Delaunay polygons and show that, up to affine equivalence, it belongs to two families of surfaces whose isometry groups include the dihedral group of the square.

The pants graph of a non-orientable surface is quasi-isometric to its Teichmüller space.

We recognize the Gromoll-Meyer sphere Sigma^7 as the geodesic join of a simple closed geodesic and a minimal subsphere Sigma^5, which can be equivariantly identified with the Brieskorn sphere W^5_3. As applications we in particular determine the full isometry group of Sigma^7, classify all closed subgroups that act fre…

The paper classifies reversible and strongly reversible elements in Hermitian isometry groups.

The paper classifies discrete complex hyperbolic triangle groups.

In this paper we study the geodesic flow on nilmanifolds equipped with a left-invariant metric. We write the underlying definitions and find general formulas for the Poisson involution. As an example we develop the Heisenberg Lie group equipped with its canonical metric. We prove that a family of first integrals giving…

We are interested in finite groups acting orientation-preservingly on 3-manifolds (arbitrary actions, ie not necessarily free actions). In particular we consider finite groups which contain an involution with nonempty connected fixed point set. This condition is satisfied by the isometry group of any hyperbolic cyclic …

For two generator free Fuchsian groups, the quotient three manifold is a genus two solid handlebody and its boundary is a hyperelliptic Riemann surface. The convex core is also a hyperelliptic Riemann surface. We find the Weierstrass points of both of these surfaces. We then generalize the notion of a hyperelliptic Rie…

The paper studies algebraic relations of first integrals on specific Lie groups.

The paper discusses conditions for gluing multiple Alexandrov spaces into an Alexandrov space.

Researchers solve Nielsen Realization problems for K3 surfaces in various categories.

Study complex hyperbolic structures on a disc orbibundle with 5 cone points.

Classifies involutions on spherical 3-manifolds.

Study classifies Calabi-Yau threefolds with non-Gorenstein involutions.

The paper studies circular evolutes and involutes of framed curves in Euclidean space.

New formula for dual knots using involutions.

The study classifies involutions on del Pezzo surfaces.

Characterizes the Legendre involution on generic frontals.

The paper defines conditions for good involutions in generalized Alexander quandles.

Study proves naturality and functoriality in a type of Heegaard Floer homology.

The paper develops a new theory for knots and 3-manifolds with involutions.

The study proves symplectic quandles cannot have good involutions.

Involution algebroids extend Lie algebroids to tangent categories.

Classifies dissecting involutions on symmetric spaces.

Involutions generate mapping class groups of infinite surfaces.

Minimal involutions generate a subgroup of nonorientable surfaces.

Study exact surgery formula in involutive Heegaard Floer homology.

Three involutions generate mapping class groups of large surfaces.

Anti-symplectic involutions connect a sphere in a symplectic surface.

Real slices of parabolic opers on Riemann surfaces are studied.

Pairs of elements in quaternionic hyperbolic space have zero measure of being strongly doubly reversible.

Classifies periodic diffeomorphisms on surfaces commuting with specific involutions.

Computed involutive knot invariants for specific pretzel knots.

Paper studies involutions generating the twist subgroup of nonorientable surfaces.

Let $Σ_{g,b}$ denote a closed orientable surface of genus $g$ with $b$ punctures and let $\rm Mod(Σ_{\textit{g,b}})$ denote its mapping class group. In [Luo] Luo proved that if the genus is at least 3, $\rm Mod(Σ_{\textit{g,b}})$ is generated by involutions. He also asked if there exists a universal upper bound, indepe…

Let F be a field of characteristic different from 2, and let $F^{n}$ denote the vector space of n-tuples of elements in F. Let ${e_{1}, ... , e_{n}}$ denote the canonical basis of $F^{n}$. Let r and s be nonnegative integers such that r + s = n, and let Q denote the nondegenerate bilinear form on $F^{n}$ such that $Q(e…

Presentations for involutions on non-orientable surfaces up to genus 5.

Three involutions generate the mapping class group for surfaces of genus 6 or more.

In this article, we classify all involutions on S^6 with 3-dimensional fixed point set. In particular, we discuss the relation between the classification of involutions with fixed point set a knotted 3-sphere and the classification of free involutions on homotopy CP^3's.

The paper defines evolutes and involutes for framed curves and their properties.