arXiv research

Study covers of surfaces, showing types and properties.

The paper constructs non-abelian covers for knots with non-trivial Alexander polynomials.

Notes on harmonic maps between manifolds, existence and regularity covered.

Non-Abelian actions are resolved using equivariant K-theory and delocalized cohomology.

We establish new strong lower bounds on the (subnormal) subgroup growth of a large class of groups. This includes the fundamental groups of all finite-volume hyperbolic 3-manifolds and all (free non-abelian)-by-cyclic groups. The lower bound is nearly exponential, which should be compared with the fastest possible subg…

Paper solves injectivity of X-ray transform on surfaces.

Study group extensions and bundles on manifolds.

New method for constructing real algebraic surfaces from complex tropical hypersurfaces.

There are few known computable examples of non-abelian surface holonomy. In this paper, we give several examples whose structure 2-groups are covering 2-groups and show that the surface holonomies can be computed via a simple formula in terms of paths of 1-dimensional holonomies inspired by earlier work of Chan Hong-Mo…

The paper studies automorphisms of Riemann surfaces and their covers.

The abstract discusses braided surfaces and their characteristic maps, linking them to algebraic and geometric properties.

Let (G) be a connected compact non-abelian Lie-group and (T) a maximal torus of (G). A torus manifold with (G)-action is defined to be a smooth connected closed oriented manifold of dimension (2\dim T) with an almost effective action of (G) such that (M^T\neq \emptyset). We show that if there is a torus manifold (M) wi…

We study the relationship between Ng's abelian cord ring and SL(2,C) characters of the two-fold branched cover $Σ(K)$. Augmentations, and their corresponding rank, play a central role in the relationship. Our study also leads to a correspondence between trace-free SL(2,C) characters of a knot complement and augmentatio…

The paper characterizes finite metacyclic subgroups in mapping class groups of surfaces.

New theory connects non-abelian bundle gerbes to abelian ones.

Extends Chern character to non-abelian cohomology, linking to physics.

We discuss a general framework for cutting constructions and reinterpret in this setting the work on non-Abelian symplectic cuts by Weitsman. We then introduce two analogous non-Abelian modification constructions for hyperkähler manifolds: one modifies the topology significantly, the other gives metric deformations. We…

The paper constructs toric vector bundles using spectral networks and non-abelianization.

The paper proves a conjecture about the positivity of the Euler characteristic for complex projective manifolds.

The paper uses non-abelian Hodge theory to generalize Kodaira vanishing theorems.

We propose a simple method to produce quandle cocycles from group cocycles, as a modification of Inoue-Kabaya chain map. We further show that, in respect to "universal central extended quandles", the chain map induces an isomorphism between their third homologies. For example, all Mochizuki's quandle 3-cocycles are sho…

We establish a Penrose-Ward transform yielding a bijection between holomorphic principal 2-bundles over a twistor space and non-Abelian self-dual tensor fields on six-dimensional flat space-time. Extending the twistor space to supertwistor space, we derive sets of manifestly N=(1,0) and N=(2,0) supersymmetric non-Abeli…

Study non-Abelian gauge theories using Poisson bracket structures.

Resolves conjectures on non-abelian Hodge loci for quasi-projective varieties.

We discuss various lifting and reduction problems for bundles and gerbes in the context of a strict Lie 2-group. We obtain a geometrical formulation (and a new proof) for the exactness of Breen's long exact sequence in non-abelian cohomology. We use our geometrical formulation in order to define a transgression map in …

In this article, we give an explicit formula to compute the non-abelian twisted sign-determined Reidemeister torsion of the exterior of a fibered knot in terms of its monodromy. As an application, we give explicit formulae for the non abelian Reidemeister torsion of torus knots and of the figure eight knot.

We review a systematic construction of the 2-stack of bundle gerbes via descent, and extend it to non-abelian gerbes. We review the role of non-abelian gerbes in orientifold sigma models, for the anomaly cancellation in supersymmetric sigma models, and in a geometric description of so-called non-geometric T-duals.

We describe a generalization of GKM theory for actions of arbitrary compact connected Lie groups. To an action satisfying the non-abelian GKM conditions we attach a graph encoding the structure of the non-abelian 1-skeleton, i.e., the subspace of points with isotopy rank at most one less than the rank of the acting gro…

This paper gives an explicit formula for the SL_2(C)-non-abelian Reidemeister torsion as defined in [Dub06] in the case of twist knots. For hyperbolic twist knots, we also prove that the non-abelian Reidemeister torsion at the holonomy representation can be expressed as a rational function evaluated at the cusp shape o…

This paper calculates the derivative of surface holonomy for non-abelian gerbes.

We construct homogeneous flat pseudo-Riemannian manifolds with non-abelian fundamental group. In the compact case, all homogeneous flat pseudo-Riemannian manifolds are complete and have abelian linear holonomy group. To the contrary, we show that there do exist non-compact and non-complete examples, where the linear ho…

Introduces non-abelian Hodge correspondence linking algebraic structures to geometry.

Paper proves injectivity of non-abelian X-ray transform on certain spaces.

We recall and partially improve four versions of smooth, non-abelian gerbes: Cech cocycles, classifying maps, bundle gerbes, and principal 2-bundles. We prove that all these four versions are equivalent, and so establish new relations between interesting recent developments. Prominent partial results we prove are a bij…

A new diffeomorphism invariant of integral homology 3-spheres is defined using a non-abelian 'quaternionic' version of the Seiberg-Witten equations.

New cohomology theory for diffeological spaces developed.

We associate Hamiltonian homological evolutionary vector fields --which are the non-Abelian variational Lie algebroids' differentials-- with Lie algebra-valued zero-curvature representations for partial differential equations.

We introduce an axiomatic framework for the parallel transport of connections on gerbes. It incorporates parallel transport along curves and along surfaces, and is formulated in terms of gluing axioms and smoothness conditions. The smoothness conditions are imposed with respect to a strict Lie 2-group, which plays the …

New method for non-abelian parallel transport in higher gauge theories.

The moduli space metric and its Kahler potential for well-separated non-Abelian vortices are obtained in U(N) gauge theories with N Higgs fields in the fundamental representation.

We study the twisted Alexander polynomial $Δ_{K,ρ}$ of a knot $K$ associated to a non-abelian representation $ρ$ of the knot group into $SL_2(\BC)$. It is known for every knot $K$ that if $K$ is fibered, then for every non-abelian representation, $Δ_{K,ρ}$ is monic and has degree $4g(K)-2$ where $g(K)$ is the genus of …

The paper explores Higgs bundles and their moduli spaces on Riemann surfaces.

Abstract: Proves non-abelian group of equivariant concordance.

Develops a new non-abelian framework for Riemann surfaces and differential equations.

We develop a Chern character map for twisted equivariant non-abelian cohomology.

Constructs moduli stacks for quiver connections and extends non-Abelian Hodge theory.

The paper connects non-abelian zeta functions, Fokker-Planck equations, and projective flat connections.

The study examines Lorentzian metrics on specific Lie groups and their curvatures.