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Related papers: Recursion Formulas for Spin Hurwitz Numbers

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We present an enhanced algorithm for exploring mirror symmetry for elliptic curves through the correspondence of algebraic and tropical geometry, focusing on Gromov-Witten invariants of elliptic curves and, in particular, Hurwitz numbers.…

Algebraic Geometry · Mathematics 2023-11-21 Firoozeh Aga , Janko Boehm , Alain Hoffmann , Hannah Markwig , Ali Traore

Hurwitz numbers count ramified covers of a Riemann surface with prescribed monodromy. As such, they are purely combinatorial objects. Tautological classes, on the other hand, are distinguished classes in the intersection ring of the moduli…

Algebraic Geometry · Mathematics 2007-05-23 Aaron Bertram , Renzo Cavalieri , Gueorgui Todorov

On a space of stable maps, the psi classes are modified by subtracting certain boundary divisors. The top products of modified psi classes, usual psi classes, and classes pulled back along the evaluation maps are called twisted descendants;…

Algebraic Geometry · Mathematics 2007-05-23 Joachim Kock

We give a recursive formula for purely real Welschinger invariants of real Del Pezzo surfaces of degree $K^2\ge 3$, where in the case of surfaces of degree $3$ with two real components we introduce a certain modification of Welschinger…

Algebraic Geometry · Mathematics 2015-01-07 Ilia Itenberg , Viatcheslav Kharlamov , Eugenii Shustin

We define the dimension 2g-1 Faber-Hurwitz Chow/homology classes on the moduli space of curves, parametrizing curves expressible as branched covers of P^1 with given ramification over infinity and sufficiently many fixed ramification points…

Algebraic Geometry · Mathematics 2007-05-23 Ian P. Goulden , David M. Jackson , Ravi Vakil

Goulden, Jackson and Vakil observed a polynomial structure underlying one-part double Hurwitz numbers, which enumerate branched covers of $\mathbb{CP}^1$ with prescribed ramification profile over $\infty$, a unique preimage over 0, and…

Algebraic Geometry · Mathematics 2020-05-04 Norman Do , Danilo Lewański

Hirzebruch surfaces provide an excellent example to underline the fact that in general symplectic manifolds, Gromov-Witten invariants might well count curves in the boundary components of the moduli space. We use this example to explain in…

Algebraic Geometry · Mathematics 2007-05-23 Holger Spielberg

The Hurwitz problem of composition of quadratic forms, or of "sum of squares identity" is tackled with the help of a particular class of $(\mathbb{Z}_2)^n$-graded non-associative algebras generalizing the octonions. This method provides an…

Commutative Algebra · Mathematics 2011-03-15 Anna Lenzhen , Sophie Morier-Genoud , Valentin Ovsienko

Multiparametric families of hypergeometric $\tau$-functions of KP or Toda type serve as generating functions for weighted Hurwitz numbers, providing weighted enumerations of branched covers of the Riemann sphere. A graphical interpretation…

Mathematical Physics · Physics 2019-07-02 A. Alexandrov , G. Chapuy , B. Eynard , J. Harnad

We obtain a formula for the number of genus one curves with a variable complex structure of a given degree on a del-Pezzo surface that pass through an appropriate number of generic points of the surface. This is done using Getzler's…

Algebraic Geometry · Mathematics 2020-01-10 Chitrabhanu Chaudhuri , Nilkantha Das

Spin Hurwitz numbers are related to characters of the Sergeev group, which are the expansion coefficients of the Q Schur functions, depending on odd times and on a subset of all Young diagrams. These characters involve two dual subsets: the…

High Energy Physics - Theory · Physics 2021-02-02 A. Mironov , A. Morozov , S. Natanzon

We derive an effective recursion for Witten's r-spin intersection numbers, using Witten's conjecture relating r-spin numbers to the Gel'fand-Dikii hierarchy (Theorem 4.1). Consequences include closed-form descriptions of the intersection…

Algebraic Geometry · Mathematics 2011-12-21 Kefeng Liu , Ravi Vakil , Hao Xu

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

We study basic geometric properties of Kottwitz-Viehmann varieties, which are certain generalizations of affine Springer fibers that encode orbital integrals of spherical Hecke functions. Based on previous work of A. Bouthier and the…

Algebraic Geometry · Mathematics 2018-05-23 Jingren Chi

We propose two conjectures on Huwritz numbers with completed $(r+1)$-cycles, or, equivalently, on certain relative Gromov-Witten invariants of the projective line. The conjectures are analogs of the ELSV formula and of the Bouchard-Mari\~no…

Algebraic Geometry · Mathematics 2017-08-22 S. Shadrin , L. Spitz , D. Zvonkine

The main object of this paper is to investigate a new class of the generalized Hurwitz type poly-Bernoulli numbers and polynomials from which we derive some algorithms for evaluating the Hurwitz type poly-Bernoulli numbers and polynomials.…

Combinatorics · Mathematics 2023-10-05 Mohamed Amine Boutiche , Mohamed Mechacha , Mourad Rahmani

In this paper, we compute the number of covers of curves with given branch behavior in characteristic p for one class of examples with four branch points and degree p. Our techniques involve related computations in the case of three branch…

Algebraic Geometry · Mathematics 2009-06-10 Irene I. Bouw , Brian Osserman

In the previous paper, we construct new subvarieties in the varieties of power sums for certain quartic hypersurfaces. In this paper, we show that these quartics coincide with the Scorza quartics of general pairs of trigonal curves and…

Algebraic Geometry · Mathematics 2009-04-24 Hiromichi Takagi , Francesco Zucconi

We consider special series in ratios of the Schur functions which are defined by integers $\textsc{f}\ge 0$ and $\textsc{e} \le 2$, and also by the set of $3k$ parameters $n_i,q_i,t_i,\,i=1,..., k$. These series may be presented in form of…

Exactly Solvable and Integrable Systems · Physics 2015-01-30 S. M. Natanzon , A. Yu. Orlov