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Related papers: Real algebraic curves and twisted Hurwitz numbers

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We show that $b$-Hurwitz numbers with a rational weight are obtained by taking an explicit limit of a Whittaker vector for the $\mathcal{W}$-algebra of type $A$. Our result is a vast generalization of several previous results that treated…

Algebraic Geometry · Mathematics 2026-04-16 Nitin K. Chidambaram , Maciej Dołęga , Kento Osuga

The Hurwitz problem asks which ramification data are realizable, that is appear as the ramification type of a covering. We use dessins d'enfant to show that families of genus 1 regular ramification data with small changes are realizable…

Geometric Topology · Mathematics 2017-09-22 Joachim König , Arielle Leitner , Danny Neftin

We define winding numbers of regular closed curves on surfaces with a nice euclidean or hyperbolic geometry. We prove that two regular closed curves are regularly homotopic if and only if they are freely homotopic and have the same winding…

Geometric Topology · Mathematics 2017-08-10 Masayuki Yamasaki

Going beyond the studies of single and double Hurwitz numbers, we report some progress towards studying Hurwitz numbers which correspond to ramified coverings of the Riemann sphere involving three nonsimple branch points. We first prove a…

Combinatorics · Mathematics 2024-07-24 Ricky Xiao-Feng Chen

We give necessary and sufficient conditions on the curvature and the torsion of a regular curve of the space forms $\h^3$ and $\s^3$ to be contained in a totally umbilical surface. In case that the curve has constant torsion, we obtain the…

Differential Geometry · Mathematics 2024-12-02 Rafael López

We introduce and begin the topological study of real rational plane curves, all of whose inflection points are real. The existence of such curves is a corollary of results in the real Schubert calculus, and their study has consequences for…

Algebraic Geometry · Mathematics 2010-03-29 Viatcheslav Kharlamov , Frank Sottile

Hurwitz numbers count ramified genus $g$, degree $d$ coverings of the projective line with with fixed branch locus and fixed ramification data. Double Hurwitz numbers count such covers, where we fix two special profiles over $0$ and…

Combinatorics · Mathematics 2018-07-11 Marvin Anas Hahn

We propose a new, conjectural recursion solution for Hurwitz numbers at all genera. This conjecture is based on recent progress in solving type B topological string theory on the mirrors of toric Calabi-Yau manifolds, which we briefly…

Algebraic Geometry · Mathematics 2008-12-04 Vincent Bouchard , Marcos Marino

In this paper, we study a certain type of Hurwitz numbers which count branched covers over the Riemann sphere admitting several branch points with fixed ramification types, one branch point with a fixed number of preimages, and one branch…

Combinatorics · Mathematics 2025-05-19 Zhiyuan Wang , Chenglang Yang

Hurwitz numbers count branched covers of the Riemann sphere with specified ramification, or equivalently, transitive permutation factorizations in the symmetric group with specified cycle types. Monotone Hurwitz numbers count a restricted…

Combinatorics · Mathematics 2012-10-15 I. P. Goulden , Mathieu Guay-Paquet , Jonathan Novak

Edge-contraction operations form an effective tool in various graph enumeration problems, such as counting Grothendieck's dessins d'enfants and simple and double Hurwitz numbers. These counting problems can be solved by a mechanism known as…

Algebraic Geometry · Mathematics 2019-08-16 Olivia Dumitrescu , Motohico Mulase

Some ball-quotient orbifolds are related by covering maps. We exploit these coverings to find infinite towers of orbifolds uniformized by the complex 2-ball and some orbifolds over K3 surfaces uniformized by the 2-ball. Corresponding…

Algebraic Geometry · Mathematics 2007-05-23 A. Muhammed Uludag

Properties of the Alexander polynomials of Hurwitz curves are investigated. A complete description of the set of the Alexander polynomials of irreducible Hurwitz curves in the terms of their roots is given.

Symplectic Geometry · Mathematics 2007-05-23 Vik. S. Kulikov

We obtain an explicit expression for the number of ramified coverings of the sphere by the torus with given ramification type for a small number of ramification points, and conjecture this to be true for an arbitrary number of ramification…

Algebraic Geometry · Mathematics 2007-05-23 P. P. Goulden , D. M. Jackson , A. Vainshtein

We construct several modular compactifications of the Hurwitz space $H^d_{g/h}$ of genus $g$ curves expressed as $d$-sheeted, simply branched covers of genus $h$ curves. These compactifications are obtained by allowing the branch points of…

Algebraic Geometry · Mathematics 2012-06-21 Anand Deopurkar

We study a generalization of the Harish-Chandra - Itzykson - Zuber integral to tensors and its expansion over trace-invariants of the two external tensors. This gives rise to natural generalizations of monotone double Hurwitz numbers, which…

Combinatorics · Mathematics 2023-10-25 Benoît Collins , Razvan Gurau , Luca Lionni

In this paper we announce some results obtained for certain algebraic functions, which we call of cyclotomic type. The main results properly resemble von Staudt-Clausen's theorem and Kummer's congruence for the Bernoulli numbers, and such…

Number Theory · Mathematics 2007-05-23 Yoshihiro Ônishi

Ekedahl, Lando, Shapiro, and Vainshtein announced a remarkable formula expressing Hurwitz numbers (counting covers of the projective line with specified simple branch points, and specified branching over one other point) in terms of Hodge…

Algebraic Geometry · Mathematics 2007-05-23 Tom Graber , Ravi Vakil

We consider the Alexander polynomial of a plane algebraic curve twisted by a linear representation. We show that it divides the product of the polynomials of the singularity links, for unitary representations. Moreover, their quotient is…

Geometric Topology · Mathematics 2007-05-23 Jose Ignacio Cogolludo , Vincent Florens

In this paper we prove the topological uniqueness of maximal arrangements of a real plane algebraic curve with respect to three lines. More generally, we prove the topological uniqueness of a maximally arranged algebraic curve on a real…

Algebraic Geometry · Mathematics 2007-05-24 G. Mikhalkin