Rectifies zero loci of certain spinors in 4D manifolds.
problem Understanding the structure of zero loci of Z/2 harmonic spinors. method Proves rectifiability and Minkowski bounds for the zero locus.
result Zero loci are 2-rectifiable and have locally finite Minkowski content.
We introduce the natural and fairly general notion of a subanalytic bundle (with a finite dimensional vector space P of sections) on a subanalytic subset X of a real analytic manifold M, and prove that when M is compact, there is a Baire subset U of sections in P whose zero-loci in X have tubular neighbou…
Paper calculates virtual dimension of spinor zero loci on 3-manifolds.
problem Computing the virtual dimension of spinor zero loci.
method Uses Kuranishi structure and index theory developed by Bruning, Seeley, and Yang.
result Proves virtual dimension is zero for 3-manifolds.
The paper studies geometric loci and their invariants in complex dynamics.
problem Analyzing geometric loci and their invariants in complex dynamics.
method Intersection theory and dynamical invariants on the flex and gothic loci.
result Determined the divisor class of the flex locus and various tautological intersection numbers on the gothic locus.
We describe and study the loci equidistant from finitely many points in the so-called complex hyperbolic geometry, i.e., in the geometry of a holomorphic 2-ball B. In particular, we show that the bisectors (= the loci equidistant from 2 points) containing the (smooth real algebraic) curve equidistant from gi…
Study Fuchsian loci in mPSLn(R)-Hitchin components of a pair of pants.
problem Understanding Fuchsian loci in mPSLn(R)-Hitchin components. method Using Bonahon-Dreyer parametrization, explicit parametrization of Fuchsian loci of a pair of pants.
result Explicit parametrization of Fuchsian loci of a pair of pants.
Researchers create explicit representations for skein algebras of small surfaces, revealing their Azumaya loci.
problem Understanding the structure and properties of skein algebras of small surfaces.
method Constructed finite-dimensional representations at all roots of unity, using explicit formulas and analyzing reducibility.
result Azumaya loci of the surfaces contain the smooth loci of classical shadow varieties, with equality for the one-punctured torus and proper containment for the four-punctured sphere.
Smooth torus actions on moduli spaces of super stable curves and maps of genus zero.
problem Constructing smooth C∗-actions on moduli spaces of super stable curves and maps of genus zero. method Using the implicit function theorem, proving smooth split atlases, and studying automorphism groups.
result Explicit descriptions of normal bundles to fixed loci in terms of spinor bundles and sections.
We study topology change in (2+1)D gravity coupling with non-Abelian SO(2,1) Higgs field from the point of view of Morse theory. It is shown that the Higgs potential can be identified as a Morse function. The critical points of the latter (i.e. loci of change of the spacetime topology) coincide with zeros of the Higgs …
In this note, we describe a procedure to construct generalized complex structures with an arbitrarily large number of type change loci on products of the circle with a connected sum of closed 3-manifolds. The loci need not be isotopic.
Study geodesics and shortest arcs on Lie groups with specific metrics.
problem Characterize geodesics and shortest arcs in sub-Riemannian metrics on Lie groups.
method Investigated left-invariant sub-Riemannian metrics on SU(1,1)imesR and SO0(2,1)imesR. result Found geodesics, shortest arcs, cut loci, and conjugate loci.
Study shows no hyperkähler fourfolds in specified conditions.
problem Identifying hyperkähler fourfolds in specific geometric settings.
method Classification and computation of Hodge numbers for fourfolds over rational homogeneous varieties.
result No hyperkähler fourfolds found in the specified conditions.
Study homotopy groups in GIT quotients using transversality methods.
problem Homotopy groups of stable loci in affine GIT.
method Infinite-dimensional transversality framework extended to GIT setting.
result Generic homotopies avoid unstable and strictly semistable strata under certain conditions.
We survey the cohomology jumping loci and the Alexander-type invariants associated to a space, or to its fundamental group. Though most of the material is expository, we provide new examples and applications, which in turn raise several questions and conjectures. The jump loci of a space X come in two basic flavors: th…
As an increasing number of genome-wide association studies reveal the limitations of attempting to explain phenotypic heritability by single genetic loci, there is growing interest for associating complex phenotypes with sets of genetic loci. While several methods for multi-locus mapping have been proposed, it is often…
Classifies Teichmüller curves in specific hyperelliptic components of meromorphic differentials.
problem Classifying Teichmüller curves in hyperelliptic components of meromorphic strata.
method Non-existence criterion based on intersections with moduli space boundary.
result Contradiction to algebraicity of candidate Teichmüller curves outside Hurwitz covers.
Study shows finiteness of Teichmueller curves in specific Prym loci.
problem Determining the existence and finiteness of Teichmueller curves in Prym loci.
method Analyzing specific Prym loci (Prym(2,1,1) and Prym(2,2)) to prove finiteness results.
result Prym(2,1,1) contains no Teichmueller curves, and Prym(2,2) at most 92 such curves.
Study Riemannian metrics on lens spaces, find cut loci and diameters.
problem Understanding Riemannian metrics on lens spaces and their geometric properties.
method Geometric control theory methods applied to axisymmetric metrics.
result Cut loci and cut times converge to sub-Riemannian structure's values.
Study Riemannian metrics on lens spaces, find cut loci and diameters.
problem Analyzing Riemannian metrics on lens spaces.
method Geometric control theory methods.
result Cut loci and cut times converge to sub-Riemannian structure's cut locus and time.
New method studies discriminantal loci of algebraic varieties.
problem Understanding discriminantal loci of algebraic varieties.
method Efficient use of groupoids to describe monodromy.
result New insights into discriminantal loci of hypersurfaces.
New upper bound for geodesic complexity derived from cut locus decompositions.
problem Understanding geodesic complexity in Riemannian manifolds.
method Study of decompositions of cut loci and their tangent fibers.
result Established a new upper bound for geodesic complexity.
Study curvature loci of 3-manifolds in R^6 and R^5.
problem Characterize curvature loci of 3-manifolds in different dimensions.
method Refine affine classification of real nets of quadrics, study singularities, and analyze systems of ternary cubics.
result Obtain generic curvature loci and singularities of 3-manifolds.
Models for 3D harmonic 1-forms and spinors near singular points.
problem Constructing models for Z/2 harmonic 1-forms and spinors in 3D near singular points. method Using symmetries of tetrahedron, octahedron, and icosahedron to construct local models on R3. result Local models are Z/2 harmonic 1-forms or spinors on R3 with zero locus consisting of rays from the origin. The paper studies conjugate loci on ellipsoids and Liouville manifolds.
problem Understanding the structure of conjugate loci on general points of ellipsoids and Liouville manifolds.
method Solving geodesic equations, investigating Jacobi fields, and analyzing the structure of conjugate loci.
result The conjugate locus of a general point on Liouville manifolds has only cuspidal edges and D4+ Lagrangian singularities. Study elliptic isometries on a matrix manifold with specific metrics.
problem Differential-geometric properties of fixed point loci.
method Explicit description and De Rham decomposition of fixed point loci.
result Explicit description and De Rham decomposition of fixed point loci.
Surveying recent results on the geometry of Jacobian loci.
problem Understanding the extrinsic geometry of Jacobian loci.
method Analyzing the Torelli map as a multiplication map and studying totally geodesic subvarieties.
result Relation between totally geodesic subvarieties and Hodge loci.
Study geodesics and shortest arcs on Lie groups with specific metrics.
problem Characterize geodesics and shortest paths on Lie groups with sub-Riemannian metrics.
method Analytical and geometric methods to find geodesics and shortest arcs.
result Found geodesics, shortest arcs, distances, and conjugate loci for specified metrics.
Study cohomology jump loci in 3-manifolds, focusing on Alexander polynomial.
problem Understanding cohomology jump loci in 3-manifolds and links.
method Analysis of characteristic and resonance varieties, using Alexander polynomial.
result Derive consequences on formality and finite-dimensional models.
Generalizes results on Bieri-Neumann-Strebel-Renz invariants and tropical varieties.
problem Relationship between Bieri-Neumann-Strebel-Renz invariants and homology jump loci.
method Uses tropical varieties to detect components of homology jump loci and generalizes results to integral coefficients.
result Provides a better upper bound for Bieri-Neumann-Strebel-Renz invariants and classifies Kähler groups.
Study geodesics on a special cylinder with arbitrary wind.
problem Global behavior of geodesics on a Randers metric cylinder.
method Solve Zermelo's navigation problem to define the Randers metric; analyze geodesics, conjugate, and cut loci.
result Characterize geodesics and their properties on the base manifold.
New potentials found for sheaves on Calabi-Yau 4-folds.
problem Understanding sheaves on Calabi-Yau 4-folds.
method Derived Quot-stacks and Lagrangian distributions.
result Globally defined −1-shifted potentials on sheaves. Let X⊂PN be a scroll over a smooth curve C and let Ł=OPN(1)∣X denote the hyperplane bundle. The special geometry of X implies that some sheaves related to the principal part bundles of Ł are locally free. The inflectional loci of X can be expressed in terms of these she…
Let M be a compact oriented 3-dimensional smooth manifold. In this paper, we construct a moduli space consisting of pairs (Σ,ψ) where Σ is a C1-embedding simple closed curve in M, ψ is a Z/2-harmonic spinor vanishing only on Σ, and ∥ψ∥L12=0. We prove that when Σ is C2, a nei…
Study Alexander invariants and cohomology jump loci in group extensions with trivial monodromy.
problem Understanding Alexander invariants and cohomology jump loci in group extensions with specific conditions.
method Analyzing integral, rational, and modular Alexander invariants and cohomology jump loci of groups as extensions with trivial algebraic monodromy.
result Established a tight relationship between Alexander invariants, characteristic varieties, and resonance varieties, leading to an inequality between Chen ranks.
This paper classifies components of meromorphic differential strata.
problem Understanding the boundary of multi-scale compactification of meromorphic differentials.
method Classifying connected components of residueless meromorphic differentials.
result Classification of connected components of strata of residueless meromorphic differentials.
The paper examines critical points in Higgs bundle moduli spaces.
problem Understanding critical points in Higgs bundle moduli spaces.
method Analyzes the Higgs field vanishing on divisors and related integrable systems.
result Topological and differential-geometric properties of critical loci are addressed.
We show that some riemannian manifolds diffeomorphic to the sphere have the property that the cut loci of general points are smoothly embedded closed disks of codimension one. Ellipsoids with distinct axes are typical examples of such manifolds.
Study on algebraic fiber spaces and their anti-canonical divisors.
problem Understanding positivity conditions and base loci of algebraic fiber spaces.
method Algebraic and analytic methods for positivity of direct image sheaves.
result Algebraic fiber spaces with semi-ample relative anti-canonical divisor have a product structure.
Study of Randers metrics on spheres with simple cut loci.
problem Understanding Randers metrics on spheres and their cut loci.
method Analyzing geodesics, conjugate, and cut loci of Finsler metrics of Randers type.
result Found new families of Randers metrics with simple cut loci.
Constructs harmonic 1-forms on K3-fibred Calabi-Yau 3-folds.
problem Analyzing harmonic 1-forms on K3-fibred Calabi-Yau 3-folds.
method Analytic construction of nowhere-vanishing harmonic 1-forms.
result Produces examples of compact 7-manifolds with holonomy G2.
Classifies connected components of meromorphic differentials with residue conditions.
problem Understanding the structure of meromorphic differentials with residue constraints.
method Analyzes the multi-scale compactification and residue conditions.
result Classified connected components of generalized strata of meromorphic differentials.
This paper is devoted to the classification of connected components of Prym eigenform loci in the strata H(2,2)^odd and H(1,1,2) in the Abelian differentials bundle in genus 3. These loci, discovered by McMullen are GL^+(2,R)-invariant submanifolds (of complex dimension 3) that project to the locus of Riemann surfaces …
Uniformizing maps and period maps are topologically tame, leading to algebraicity of Hodge loci.
problem Understanding the algebraicity of Hodge loci in arithmetic quotients.
method Proving topological tameness of uniformizing maps and period maps, applying Peterzil-Starchenko's o-minimal GAGA theorem.
result The Hodge locus of (S,V) is a countable union of algebraic subvarieties of S. We prove a Lefschetz hyperplane theorem for the determinantal loci of a morphism between two holomorphic vector bundles E and F over a complex manifold under the condition that $E^*\ox F$ is Griffiths k-positive. We apply this result to find some homotopy groups of the Brill-Noether loci for a generic curve.
Study of longest arcs and cut loci in deformed anti de-Sitter spaces.
problem Existence and properties of time-like cycles in deformed Lorentzian manifolds.
method Analysis of universal covering, admissible curves, and Lorentzian geodesics.
result Identification of cut time and cut locus in deformed anti de-Sitter spaces.
We study the moduli space of SU(3) structure manifolds X that form the internal compact spaces in four-dimensional N=1/2 domain wall solutions of heterotic supergravity with flux. Together with the direction perpendicular to the four-dimensional domain wall, X forms a non-compact 7-manifold Y with torsionful G2 structu…
The study characterizes a complex curve of residueless meromorphic differentials on elliptic curves.
problem Characterizing the locus of residueless meromorphic differentials on elliptic curves.
method Multi-scale compactification of strata, formulas for genus and degree of maps, distinguishing components.
result Complete classification of connected components of residueless loci in exceptional strata.
Study the boundary of Riemann surfaces with abelian automorphisms.
problem Characterize the boundary of Riemann surfaces with abelian automorphisms.
method Analyze the moduli space and its Deligne-Mumford compactification, focusing on equisymmetric loci.
result Describe the topological strata at the boundary for hyperelliptic and cyclic p-gonal actions.