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Related papers: Welschinger invariants revisited

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For any fixed $1 \leq \ell \leq 9$, we characterize all Wahl singularities that appear in degenerations of del Pezzo surfaces of degree $\ell$. This extends the work of Manetti and Hacking-Prokhorov in degree $9$, where Wahl singularities…

Algebraic Geometry · Mathematics 2025-07-14 Giancarlo Urzúa , Juan Pablo Zúñiga

We first recall Solomon's relations for Welschinger's invariants counting real curves in real symplectic fourfolds, announced in \cite{Jake2} and established in \cite{RealWDVV}, and the WDVV-style relations for Welschinger's invariants…

Symplectic Geometry · Mathematics 2023-07-31 Xujia Chen , Aleksey Zinger

This is the first in a series of papers where we prove a conjecture of Deser and Schwimmer regarding the algebraic structure of ``global confor- mal invariants"; these are defined to be conformally invariant integrals of geometric scalars.…

Differential Geometry · Mathematics 2009-12-18 Spyros Alexakis

We establish a formula for the Gromov-Witten-Welschinger invariants of $\mathbb CP^3$ with mixed real and conjugate point constraints. The method is based on a suggestion by J. Koll\'ar that, considering pencils of quadrics, some real and…

Algebraic Geometry · Mathematics 2016-03-04 Erwan Brugalle , Penka Georgieva

We obtain a formula for the number of genus one curves with a fixed complex structure of a given degree on a del-Pezzo surface that pass through an appropriate number of generic points of the surface. This enumerative problem is expressed…

Algebraic Geometry · Mathematics 2025-02-21 Indranil Biswas , Ritwik Mukherjee , Varun Thakre

I first recall the various problems of real enumerative geometry out of which I could extract some integer valued invariants, providing some real counterpart to Gromov-Witten invariants. I then discuss sharpness of the lower bounds given by…

Algebraic Geometry · Mathematics 2010-03-16 Jean-Yves Welschinger

We characterize transversality, non-transversality properties on the moduli space of genus 0 stable maps to a rational projective surface. If a target space is equipped with a real structure, i.e, anti-holomorphic involution, then the…

Algebraic Geometry · Mathematics 2011-11-10 Seongchun Kwon

We study singular del Pezzo surfaces that are quasi-smooth and well-formed weighted hypersurfaces. We give an algorithm how to classify all of them.

Algebraic Geometry · Mathematics 2025-09-03 Erik Paemurru

In our previous paper we have elaborated a certain signed count of real lines on real projective n-dimensional hypersurfaces of degree 2n-1. Contrary to the honest "cardinal" count, it is independent of the choice of a hypersurface, and by…

Algebraic Geometry · Mathematics 2019-11-19 Sergey Finashin , Viatcheslav Kharlamov

We classify smooth del Pezzo surfaces whose alpha-invariant of Tian is bigger than one.

Algebraic Geometry · Mathematics 2011-01-12 Ivan Cheltsov , Andrew Wilson

I prove new local inequality for divisors on smooth surfaces, describe its applications, and compare it to a similar local inequality that is already known by experts.

Algebraic Geometry · Mathematics 2013-11-22 Ivan Cheltsov

This is the last in a series of papers where we prove a conjecture of Deser and Schwimmer regarding the algebraic structure of ``global conformal invariants''; these are defined to be conformally invariant integrals of geometric scalars.…

Differential Geometry · Mathematics 2009-12-21 Spyros Alexakis

We define a quadratically enriched count of rational curves in a given divisor class passing through a collection of points on a del Pezzo surface $S$ of degree $\geq 3$ over a perfect field $k$ of characteristic $\neq 2,3.$ When $S$ is…

Algebraic Geometry · Mathematics 2026-03-03 Jesse Leo Kass , Marc Levine , Jake P. Solomon , Kirsten Wickelgren

We prove that the quadratically enriched count of rational curves in a smooth toric del Pezzo surface passing through $k$-rational points and pairs of conjugate points in quadratic field extensions $k\subset k(\sqrt{d_i})$ can be determined…

Algebraic Geometry · Mathematics 2026-03-19 Andrés Jaramillo Puentes , Hannah Markwig , Sabrina Pauli , Felix Röhrle

This is the fourth in a series of papers where we prove a conjecture of Deser and Schwimmer regarding the algebraic structure of ``global conformal invariants''; these are defined to be conformally invariant integrals of geometric scalars.…

Differential Geometry · Mathematics 2009-12-21 Spyros Alexakis

In this paper we introduce broccoli curves, certain plane tropical curves of genus zero related to real algebraic curves. The numbers of these broccoli curves through given points are independent of the chosen points - for arbitrary choices…

Algebraic Geometry · Mathematics 2013-09-12 Andreas Gathmann , Hannah Markwig , Franziska Schroeter

The purpose of this paper is: 1) to explain the Seiberg-Witten invariants, 2) to show that - on a K\"ahler surface - the solutions of the monopole equations can be interpreted as algebraic objects, namely effective divisors, 3) to give - as…

alg-geom · Mathematics 2008-02-03 Andrei Teleman , Christian Okonek

Let $G\subset SO(4)$ denote a finite subgroup containing the Heisenberg group. In these notes we classify all these groups, we find the dimension of the spaces of $G$-invariant polynomials and we give equations for the generators whenever…

Algebraic Geometry · Mathematics 2007-05-23 Alessandra Sarti

For every smooth del Pezzo surface $S$, smooth curve $C\in|-K_{S}|$ and $\beta\in(0,1]$, we compute the $\alpha$-invariant of Tian $\alpha(S,(1-\beta)C)$ and prove the existence of K\"ahler--Einstein metrics on $S$ with edge singularities…

Algebraic Geometry · Mathematics 2016-07-12 Ivan Cheltsov , Jesus Martinez-Garcia

Manin's conjecture for the asymptotic behavior of the number of rational points of bounded height on del Pezzo surfaces can be approached through universal torsors. We prove several auxiliary results for the estimation of the number of…

Number Theory · Mathematics 2009-02-13 Ulrich Derenthal