Minimal surfaces and curves can have singularities removed by isotopy.
problem Removing singularities of minimal surfaces and curves.
method Isotopy through conformal minimal surfaces and null holomorphic curves.
result Branch points and complete ends of finite total curvature can be removed.
The paper studies constraint maps with singularities and free boundaries, proving continuity near singularities and optimality.
problem Analyzing the structure of constraint maps with singularities and free boundaries.
method Establish continuity near singularities using a new quantitative unique continuation principle, and investigate the presence of branch points leading to new singularities.
result Topological singularities can only lie in the interior of the contact set in the uniformly convex setting, and the optimality of this result is proven.
New results on hypersurfaces show no branch points, improving smoothness.
problem Analyzing area minimising hypersurfaces mod p without branch points.
method General analysis of immersed stable minimal hypersurfaces with alternating orientation.
result Area minimising hypersurfaces mod p do not admit immersed branch points.
Complex wrinkling patterns emerge in non-Euclidean elastic sheets due to energy minimization.
problem Understanding hierarchical buckling patterns in non-Euclidean elastic sheets.
method Minimizing elastic energy to explain complex wrinkling patterns.
result Branch-point singularities are key to generating complex wrinkling patterns.
Branch points of a real 2-surface S in a 4-manifold M generalize the branch points of complex curves in complex surfaces: for example, they can occur as singularities of minimal surfaces. We investigate such a branch point p when S is topologically embedded in M. It defines a link L(p), the components of which are clos…
New estimates show unique cylindrical blow-ups for Dirichlet energy minimizers near singular points.
problem Analyzing the singularities of multi-valued Dirichlet energy minimizers.
method Developed estimates to study asymptotic behavior and used techniques from Wickramasekera's work.
result The singular set of a Dirichlet energy minimizer is countably (n−2)-rectifiable. New exponential decay estimate for Hermitian Yang-Mills metrics near branch points.
problem Understanding the behavior of Hermitian Yang-Mills metrics near branch points.
method Local radial solutions, global gluing construction, exponential estimate near branch points.
result Exponential decay estimate for local radial solutions near branch points.
Stability of branched immersions with energy constraints.
problem Stability of branched Willmore immersions with bounded energy.
method Refined analysis of fourth-order differential operators with regular singularities.
result Sum of Morse index and nullity is lower semi-continuous.
Analyzes branch points of area-minimizing currents with non-2 planar frequency.
problem Understanding the structure of area-minimizing currents near branch points.
method Intrinsic frequency function and geometric arguments avoiding center manifolds.
result Establishes higher order asymptotics and topological control near branch points.
New height estimate for area minimizing currents, leading to unique tangent cones and decay properties.
problem Analyzing singularities of area minimizing currents.
method Height estimate, decay estimates, techniques inspired by previous works.
result Locally area minimizing currents have a unique tangent cone at almost every point and decay rapidly to a unique tangent plane at branch points.
We prove that finite area isolated singularities of surfaces with constant positive curvature in R^3 are removable singularities, branch points or immersed conical singularities. We describe the space of immersed conical singularities of such surfaces in terms of the class of real analytic closed locally convex curves …
Study on singularities of area-minimizing currents, focusing on frequency and branch points.
problem Understanding the nature of singular points in area-minimizing currents.
method Intrinsic frequency function and decomposition theorem for singular set.
result Established properties of the planar frequency function and decomposition of singular set.
We generalise the classical Chern-Gauss-Bonnet formula to a class of 4-dimensional manifolds with finitely many conformally flat ends and singular points. This extends results of Chang-Qing-Yang in the smooth case. Under the assumptions of finite total Q curvature and positive scalar curvature at the ends and at the si…
HADES detects data singularities quickly and accurately.
problem Detecting singularities in data efficiently.
method Kernel goodness-of-fit test based on differential geometry and optimal transport theory.
result Correctly detects singularities with high probability.
The paper studies how surfaces move by mean curvature flow and what happens at singular points.
problem Understanding the behavior of surfaces moving by mean curvature flow at singular points.
method Proves that tangent flows at singular times are smooth shrinkers, with a new local Gauss-Bonnet formula.
result Smooth shrinkers without branch points if the initial surface is embedded in 3-manifold.
Discrete theory for rational maps improved by generalized branch points.
problem Discretization effects in locating branch points in circle packings.
method Introducing generalized branch points that can be positioned anywhere in the geometry.
result Fixed flaws in discrete Ahlfors and Weierstrasse functions using generalized branching.
The study investigates how branch points affect the shape and mechanics of hyperbolic surfaces.
problem Understanding the role of branch points in the shape and mechanics of hyperbolic surfaces.
method Developed a discrete differential geometric (DDG) approach to study deformations of hyperbolic objects with distributed branch points.
result Branch points influence the overall morphology of hyperbolic surfaces without concentrating energy, leading to sub-exponential growth in maximum curvature.
In the 1980's, Almgren developed a theory of multi-valued Dirichlet energy minimizing functions on n dimensional domains and used it, in an essential way, to bound the Hausdorff dimension of the singular sets of area minimizing rectifiable currents of dimension n and codimension ≥2. Recent work of the second …
Paper finds new realizable data for maps with three branch points.
problem Existence of rational maps with specific branch points.
method New families of branch data identified through football decomposition method.
result Identifies new realizable branch data and exceptional data.
In this paper we classify branched Willmore spheres with at most three branch points (including multiplicity), showing that they may be obtained from complete minimal surfaces in R3 with ends of multiplicity at most three. This extends the classification result of Bryant. We then show that this may be applied to …
Random free group outer automorphisms are geometric and have nongeometric attracting trees.
problem Understanding the structure of random outer automorphisms of free groups.
method Analyzing the Whitehead graph and ideal Whitehead graph of random outer automorphisms.
result The attracting tree of a random outer automorphism is a nongeometric R-tree with all branch points trivalent.
Study continuous deformations of branched projective structures on surfaces, preserving holonomy and branch points.
problem Continuous deformations of branched projective structures on closed surfaces of genus g≥2. method Schiffer variations and analysis of canonical divisors.
result Branch points are necessarily arranged on a canonical divisor when the underlying complex structure is infinitesimally preserved.
We deform a minimal disk in R4 with a branch point into symplectic minimally immersed disks with only transverse double points.
Study branched coverings of singular (G,X)-manifolds, solving open questions.
problem Understanding branched coverings of singular (G,X)-manifolds.
method Developed a Galois theory for branched coverings, constructed developping maps for singular manifolds.
result Solved open questions and constructed new examples related to singular (G,X)-manifolds.
The homotopy theory of topological defects in ordered media fails to completely characterize systems with broken translational symmetry. We argue that the problem can be understood in terms of the lack of rotational Goldstone modes in such systems and provide an alternate approach that correctly accounts for the intera…
We desingularize a branch point p of a minimal disk F0(D) in R4 through immersions Ft's which have only transverse double points and are branched covers of the plane tangent to F0(D) at p. If F0 is a topological embedding and thus defines a knot in a sphere/cylinder around …
Racks do not give us invariants of surface-knots in general. For example, if a surface-knot diagram has branch points (and a rack which we use satisfies some mild condition), then it admits no rack colorings. In this paper, we investigate rack colorings for surface-knot diagrams without branch points and prove that rac…
Until now, the only known maximal surfaces in Minkowski 3-space of finite topology with compact singular set and without branch points were either genus zero or genus one, or came from a correspondence with minimal surfaces in Euclidean 3-space given by the third and fourth authors in a previous paper. In this paper, w…
Closed geodesic nets on surfaces have limited branch points
problem Geodesic nets on surfaces
method Bounding the number of branch points
result Proving a bound on branch points for closed geodesic nets
Novel defects in hyperbolic sheets explain complex wrinkling patterns in nature.
problem Understanding complex wrinkling patterns in thin elastic hyperbolic surfaces.
method Non-Euclidean plate theory and investigation of branch points.
result Branch points are natural defects in hyperbolic sheets, influencing their morphology robustly.
We study knots in S3 obtained by the intersection of a minimal surface in R4 with a small 3-sphere centered at a branch point. We construct examples of new minimal knots. In particular we show the existence of non-fibered minimal knots. We show that simple minimal knots are either reversible or …
The paper explores positivity and irreducibility in Hurwitz spaces related to differentials of the second kind.
problem Positivity and irreducibility in Hurwitz spaces of certain covers of the projective line.
method Analyzes strata of differentials of the second kind with fixed multiplicities of zeros and poles, and applies this to show positivity and irreducibility in Hurwitz spaces.
result The Hurwitz spaces of degree d, genus g covers of P1 with pure branching at all but possibly one branch point are irreducible under certain conditions. Suppose that f and g are Markov surjections, each defined on a wedge of circles, each fixing the branch point and having the branch point as the only critical value. We show that if the points in the inverse limit spaces associated with f and g corresponding to the branch point are distinguished then these inverse limi…
We prove that if S is a closed compact surface of negative Euler characteristic, and if R is a quasi-Fuchsian representation in PSL(2,C), then the deformation space M(k,R) of branched projective structures on S with total branching order k and holonomy R is connected, as soon as k>0. Equivalently, two branched projecti…
Machine learning finds Z/2 eigenfunctions on a sphere.
problem Finding Z/2 eigenfunctions on the sphere.
method Created a multivalued neural network and used JAX to implement it. Fixed branch points at tetrahedron and cube vertices, and allowed AI to move them in the third case.
result Found Z/2 eigenfunctions for three cases.
Introduces CSST and characterizes its topology.
problem Characterize the topology of the continuum random tree.
method Introduce continuum self-similar tree (CSST) and apply it.
result Characterizes the topology of CSST and other trees.
The paper explores rational functions with 3 branching points on the Riemann sphere.
problem Existence of rational functions with specific branching points.
method Utilizes complex analysis to establish properties of rational functions.
result Identifies new types of exceptional branching data.
Researchers compute specific Hurwitz numbers for branched covers.
problem Computing the number of equivalence classes of surface branched covers.
method Combinatorial method based on Gronthendieck's dessins d'enfant.
result Explicit arithmetic formulae for weak Hurwitz numbers are derived.
For distinct points p and q in a two-dimensional Riemannian manifold, one defines their mediatrix Lpq as the set of equidistant points to p and q. It is known that mediatrices have a cell decomposition consisting of a finite number of branch points connected by Lipschitz curves. This paper establishes addi…
Proves resurgent nature of a series solution to deformed Painlevé I equation.
problem Analyzing the resurgent nature of a series solution to the deformed Painlevé I equation.
method Proves resurgent nature through formal ℏ-power series solution and Borel summability. result Borel transform defines a global multivalued holomorphic function on a Fermat quintic surface.
Elementary proof shows no specific torus to sphere cover with certain branching points.
problem Existence of specific branched covers between torus and sphere.
method Elementary topological proof using properties of the torus.
result No such branched cover exists with specified branching points.
Let X=G/K be a symmetric space of noncompact type and let L be the Laplacian associated with a G-invariant metric on X. We show that the resolvent kernel of L admits a holomorphic extension to a Riemann surface depending on the rank of the symmetric space. This Riemann surface is a branched cover of the complex plane w…
We show that any 2-valued C^{1, α} (α\in (0, 1)) function u = {u_{1}, u_{2}} on an open ball B in {\mathbb R}^{n} with values u_{1}, u_{2} \in {\mathbb R}^{k} whose graph, viewed as a varifold with multiplicity 2 at points where u_{1} = u_{2} and with multiplicity 1 at points where u_{1}, u_{2} are distinct, is station…
Character variety of a 6-punctured sphere mapped to CP^3 with specific branch points.
problem Characterizing the traceless SU(2) character variety of a 6-punctured 2-sphere.
method Analysis of 2-fold branched cover and application of Narasimhan-Ramanan theorem.
result Character variety corresponds to a 2-fold branched cover of CP^3 over a singular Kummer surface.
Minimal surfaces in CAT(0) spaces are well-behaved except at a few points.
problem Understanding the structure of minimal surfaces in CAT(0) spaces.
method Established properties of minimal surfaces and proved Fary-Milnor's theorem.
result Minimal discs in CAT(0) spaces are local embeddings away from a finite set of branch points.
Rigidity of critical eigensections on spheres proven.
problem Rigidity of critical eigensections on spheres.
method Proved rigidity of critical eigensections through SO(3)-rotations.
result Minimal non-degenerate critical eigensections are deformation rigid.
Study proves Lojasiewicz inequalities for harmonic maps near simple bubble trees.
problem Analyzing harmonic maps near simple bubble trees.
method Proves Lojasiewicz inequalities for harmonic maps close to simple bubble trees.
result Obtains new results on the convergence of harmonic map flow and energy spectrum.
Researchers compute specific types of branched surface covers.
problem Counting specific types of branched surface covers.
method Combinatorial method based on Grothendieck's dessins d'enfant.
result Explicit formulae for the number of covers in terms of local degrees.