The paper proves abelian convexity theorems using Kempf-Ness functions.
problem Establishing convexity along orbits in general settings.
method Using Kempf-Ness functions to prove abelian convexity theorems.
result Short proofs of Atiyah-Guillemin-Sternberg theorem and abelian convexity for gradient maps.
The paper characterizes convex co-compact groups with one-dimensional boundary faces.
problem Characterizing convex co-compact groups with specific boundary properties.
method Proving relative hyperbolicity and using coarse Hilbert dimension.
result Convex co-compact groups with one-dimensional boundary faces are relatively hyperbolic.
In this paper we extend the results of Kirwan et alii on convexity properties of the moment map for Hamiltonian group actions, and on the connectedness of the fibers of the moment map, to the case of non-compact orbifolds. Our motivation is twofold. First, the category of orbifolds is important in symplectic geometry b…
Study convexity properties of gradient map on probability measures.
problem Properties of gradient map on probability measures on submanifolds.
method Analysis of Kähler manifolds and Lie group actions.
result Convexity results for gradient map in Abelian case, extension to non-Abelian case.
Let Λ be a finite abelian group. A dynamical system with transformation group Λ is a triple (A,Λ,α), consisting of a unital locally convex algebra A, the finite abelian group Λ and a group homomorphism $α:Λ\rightarrow\Aut(A)$, which induces an action of Λ on A. In this paper we present a new, geometricall…
This paper gives the first example of a unipotent group that is not virtually abelian and preserves a strictly convex domain.
Lie groups with bi-invariant distance are products of abelian and compact groups.
problem Characterizing Lie groups with bi-invariant distances.
method Analyzing the structure of Lie groups and introducing a Finsler norm.
result The sectional curvature of bi-invariant distances is non-negative and vanishes only for abelian subalgebras.
Local mixing theorem for abelian covers of hyperbolic 3-manifolds.
problem Mixing properties of frame flows on abelian covers.
method Local mixing theorem for horospherical subgroups on abelian covers.
result Classification of invariant measures for horospherical subgroups.
In the first part of the paper, we build a foundation for further work on Hamiltonian actions on symplectic orbifolds. Most importantly we prove the orbifold versions of the abelian connectedness and convexity theorems. In the second half, we prove that compact symplectic orbifolds with completely integrable torus acti…
We prove that all elements of infinite order in Out(Fn) have positive translation lengths; moreover, they are bounded away from zero. Consequences include a new proof that solvable subgroups of Out(Fn) are finitely generated and virtually abelian and the new result that such subgroups are quasi-convex.
Stability of non-abelian X-ray transform proven in higher dimensions.
problem Recovering matrix potentials from scattering data in higher dimensions.
method Injectivity proof using a novel method by Uhlmann-Vasy, with quantitative improvements.
result Hölder-type stability estimate established for non-abelian X-ray transform.
We show that for acylindrically hyperbolic groups Γ (with no nontrivial finite normal subgroups) and arbitrary unitary representation ρ of Γ in a (nonzero) uniformly convex Banach space the vector space Hb2(Γ;ρ) is infinite dimensional. The result was known for the regular representations on ℓp(Γ) with …
We study a compact invariant convex set E in a polar representation of a compact Lie group. Polar rapresentations are given by the adjoint action of K on p, where K is a maximal compact subgroup of a real semisimple Lie group G with Lie algebra g=k⊕p. If …
New method finds lattice polygons that can be dissected into triangles with integer areas.
problem Finding lattice polygons that can be dissected into triangles with integer areas.
method A new version of Sperner's Lemma.
result Simple and complete description of lattice polygons that can be dissected into triangles with integer areas.
We establish a close connection between stable commutator length in free groups and the geometry of sails (roughly, the boundary of the convex hull of the set of integer lattice points) in integral polyhedral cones. This connection allows us to show that the scl norm is piecewise rational linear in free products of Abe…
New theory connects non-abelian bundle gerbes to abelian ones.
problem Challenges in extending higher gauge theory beyond fake-flat sector.
method Developed a comprehensive theory of adjusted connections on non-abelian bundle gerbes.
result Established a new coordinate-independent formulation of lifting theorem.
Chern-Simons theory on a closed contact three-manifold is studied when the Lie group for gauge transformations is compact, connected and abelian. A rigorous definition of an abelian Chern-Simons partition function is derived using the Faddeev-Popov gauge fixing method. A symplectic abelian Chern-Simons partition functi…
Introduces semi-abelian generalized complex structures.
problem Deformation theory of abelian complex structures.
method Definition and examples of semi-abelian generalized complex structures.
result Illustration of new concept with examples.
Quantum Kirwan maps between K-theories of G-varieties and GIT quotients.
problem Constructing maps between K-theories of G-varieties and their GIT quotients.
method Formal construction of maps in quantum K-theory, using equivariant and non-equivariant quantum K-theory.
result Presentation of quantum K-theory for smooth proper toric DM stacks.
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…
Classifies SU(2)-abelian graph manifolds with a single JSJ torus.
problem Classifying SU(2)-abelian 3-manifolds.
method Using Seifert coefficients and Heegaard Floer homology.
result SU(2)-abelian graph manifolds are Heegaard Floer homology L-spaces.
Study locally conformally balanced metrics on specific Lie algebras.
problem Characterize and classify locally conformally balanced metrics on almost abelian Lie algebras.
method Characterizations and classifications based on specific properties of Lie algebras.
result Classification of six-dimensional almost abelian Lie algebras with locally conformally balanced metrics.
The paper classifies invariant structures on complex almost Abelian groups.
problem Investigating invariant geometric structures on almost Abelian Lie groups.
method Explicit formulas for Haar measures, modular function, and generator fields were derived.
result All invariant tensor fields have constant coefficients in the invariant frame.
Harmonic almost complex structures on specific Lie groups and solvmanifolds identified.
problem Characterizing harmonic almost complex structures on almost abelian Lie groups and solvmanifolds.
method Adapted Gray-Hervella classification to almost abelian Lie groups, characterized harmonic structures.
result Examples of harmonic almost complex structures in different Gray-Hervella classes on compact almost abelian solvmanifolds.
3-manifolds with two abelian-filled spaces.
problem Finding 3-manifolds with multiple abelian-filled spaces.
method Constructing 3-manifolds with specific embedding properties.
result 3-manifolds with at least two abelian-filled spaces.
Abstract: Proves non-abelian group of equivariant concordance.
problem Equivariant concordance group non-abelian
method Infinite family of nontrivial commutators
result Equivariant concordance group is not abelian
Characterizes quandles with abelian inner automorphisms.
problem Understanding quandles with specific automorphism properties.
method Generalizes previous work to construct new quandles.
result Homogeneous quandles with abelian inner automorphisms are abelian extensions of trivial quandles.
Paper explores connection cochain in abelian extensions and its relation to connection forms.
problem Understanding the connection cochain in abelian extensions.
method Apply Moriyoshi's connection cochain concept to abelian extensions and relate it to connection 1-forms.
result Established the relationship between connection cochain and connection 1-forms in abelian extensions.
New effective divisors found in moduli spaces from abelian differentials.
problem Computing effective divisors in moduli spaces Mg,n. method Utilizing maps between moduli spaces and the degeneration of abelian differentials.
result Many new classes of effective divisors computed and reproduced known results.
Extends Chern character to non-abelian cohomology, linking to physics.
problem Generalizing Chern character to non-abelian cohomology.
method Leveraging dg-algebraic rational homotopy theory and de Rham theorem.
result Generalizes Chern-Dold character, Chern-Weil homomorphism, and Cheeger-Simons homomorphism.
Study of abelian structures on odd-dimensional Lie algebras and their geometric properties.
problem Characterizing abelian structures on odd-dimensional Lie algebras.
method Introducing and analyzing abelian almost contact and almost 3-contact structures, and their compatibility conditions.
result Classification of 5-dimensional Sasakian Lie algebras and 7-dimensional abelian almost 3-contact Lie algebras.
The paper classifies fixed subgroups of endomorphisms in free-abelian times surface groups.
problem Characterizing fixed subgroups of endomorphisms in specific group structures.
method Study of endomorphisms, classification of fixed subgroups, and equivalent conditions for end-fixed subgroups.
result Complete classification of fixed subgroups in free-abelian times surface groups.
Study abelianization of Lie algebroids and groupoids, providing conditions for existence.
problem Existence conditions for abelianization of Lie algebroids and groupoids.
method Investigation of abelianization for Lie algebroids and groupoids, providing necessary and sufficient conditions.
result Necessary and sufficient conditions for the existence of abelianization in both Lie algebroids and groupoids.
Characterizes structures preserved by groups in high-dimensional spaces.
problem Understanding the space of structures preserved by group actions.
method Analyzes character varieties and properties of manifolds.
result Character images are closed in the character variety under certain conditions.
Study of complex and Hermitian structures on specific Lie groups.
problem Classifying Lie groups with specific geometric structures.
method Analysis of left-invariant structures on almost abelian Lie groups.
result Classification of six-dimensional generalized Kähler almost abelian Lie groups.
Study transcendence of abelian differential periods from bi-algebraic perspective.
problem Arithmetic and functional transcendence of periods of abelian differentials.
method Bi-algebraic structure on strata of abelian differentials.
result Characterization of arithmetic points and proof of linear bi-algebraic curves.
We classify up to coarse equivalence all countable abelian groups of finite torsion free rank. The Q-cohomological dimension and the torsion free rank are the two invariants that give us such classification. We also prove that any countable abelian group of finite torsion free rank is coarsely equivalent to Z^n + H whe…
Study pseudo-Kähler structures on almost abelian solvmanifolds.
problem Classify pseudo-Kähler structures on almost abelian Lie algebras.
method Analyzing invariant structures on solvmanifolds with specific Lie algebra properties.
result Classification of pseudo-Kähler structures on almost abelian Lie algebras.
Study balanced Hermitian structures on almost abelian Lie algebras, classifying six-dimensional cases.
problem Classify balanced Hermitian structures on almost abelian Lie algebras.
method Classify six-dimensional almost abelian Lie algebras with balanced structures, investigate flow of balanced metrics and anomaly flow.
result Prove conjecture for compact almost abelian solvmanifolds with left-invariant complex structures.
Quantum trace maps abelian character varieties to SL2 character varieties.
problem Classifying irreducible representations of Chekhov-Fock algebras.
method Non-commutative deformation of algebraic morphisms.
result Induces birational morphism between torus and SL2 character variety.
Complete Calabi-Yau metrics on abelian fibrations over complex space.
problem Constructing complete Calabi-Yau metrics on noncompact abelian fibrations.
method Using abelian fibrations over C, we construct complete Calabi-Yau metrics and provide compactification. result We provide a compactification for the abelian fibration X such that the compactified variety has a negative canonical bundle. Fibers of abelian varieties over curves can be approximated algebraically.
problem Approximating fibers of abelian varieties over curves algebraically.
method Proving the existence of algebraic approximations for fibrations.
result Fibrations with abelian varieties over curves have algebraic approximations.
Study on CKY forms on almost abelian Lie groups, proving parallelism and characterizing non-parallel cases.
problem Characterizing CKY forms on almost abelian Lie groups and proving parallelism.
method Analyzing almost abelian metric Lie algebras, proving parallelism for CKY forms, and classifying cases up to dimension 5.
result CKY forms are parallel on almost abelian Lie algebras, with exceptions for p=1 and p=n−1. Introduces G-Tutte polynomials for abelian group arrangements.
problem Counting homomorphisms from abelian groups to G. method Defines G-Tutte polynomials as a generalization of various polynomials. result Carries topological and enumerative information of abelian Lie group arrangements.
The paper characterizes splittings of certain CAT(0) groups and their boundaries.
problem Characterizing splittings of one-ended CAT(0) groups with isolated flats.
method General convex splitting theorem for CAT(0) groups, analysis of visual boundaries.
result Characterization of locally connected visual boundaries based on group splittings.
Proves even degrees can be realized in Abelian differential strata.
problem Realizing even degrees as stretch factors in Abelian differentials.
method Analyzes Thurston-Veech stretch factors in moduli spaces.
result Every even degree 2d≤2g is realized in Abelian differentials. The paper constructs toric vector bundles using spectral networks and non-abelianization.
problem Understanding how holomorphic vector bundles arise from spectral networks and non-abelianization.
method Constructing toric vector bundles on complete toric surfaces via spectral networks and non-abelianization.
result The moduli space of rank 2 toric vector bundles over toric surfaces admits an A-type X-cluster structure. Study shows Kahler extensions of abelian groups are products or related to mapping class groups.
problem Characterizing Kahler extensions of abelian groups.
method Surface topology and restrictions on Kahler groups.
result Kahler extensions are virtually products or related to mapping class groups.