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Related papers: Effective cone of $overline{M}_{0,n}$ for odd $n$

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We investigate the birational geometry (in the sense of Mori's program) of the moduli space of rank 2 semistable parabolic vector bundles on a rational curve. We compute the effective cone of the moduli space and show that all birational…

Algebraic Geometry · Mathematics 2015-07-15 Han-Bom Moon , Sang-Bum Yoo

We prove that the moduli space of $n$-pointed stable maps $\overline{M}_{0,n}(\mathbb{P}^1,1)$ is a Mori dream space whenever the moduli space $\overline{M}_{0,n+3}$ of $(n+3)$-pointed rational curves is. We also show that…

Algebraic Geometry · Mathematics 2020-01-17 Claudio Fontanari

We obtain new information about divisors on the $d-$th symmetric power $C_{d}$ of a general curve $C$ of genus $g \geq 4.$ This includes a complete description of the effective cone of $C_{g-1}$ and a partial computation of the volume…

Algebraic Geometry · Mathematics 2009-05-09 Yusuf Mustopa

The paper is devoted to the problem of exact calculation of the norms in ideal spaces for monotone operators on the cones of functions with monotonicity properties. We implement a general approach to this problem that covers many concrete…

Functional Analysis · Mathematics 2021-01-19 E. G. Bakhtigareeva , M. L. Goldman

We determine five extremal effective rays of the four-dimensional cone of effective surfaces on the toroidal compactification $\overline{\mathcal A}_3$ of the moduli space ${\mathcal A}_3$ of complex principally polarized abelian…

Algebraic Geometry · Mathematics 2022-02-14 Samuel Grushevsky , Klaus Hulek

We consider the ${\mathbb Z}^n$-graded algebra of global sections of line bundles generated by the standard line bundles $L_1,\ldots,L_n$ on $\bar{M}_{0,n}$. We find a simple presentation of this algebra by generators and quadratic…

Algebraic Geometry · Mathematics 2024-06-03 Alexander Polishchuk , Eric Rains

This paper is an expository survey of results about the effective divisors on moduli spaces, with a focus on what is known about the effective cones of moduli spaces of stable curves and of principally polarized abelian varieties. This…

Algebraic Geometry · Mathematics 2015-03-20 Dawei Chen , Gavril Farkas , Ian Morrison

We study the log canonical models of the moduli space MBar_{0,n} of pointed stable genus zero curves with respect to the standard log canonical divisors K+aD, where D denotes the boundary. In particular we show that, as a formal consequence…

Algebraic Geometry · Mathematics 2007-09-27 Matthew Simpson

Let $X$ be a smooth projective variety over the complex numbers. One knows by the Cone Theorem that the closed cone of curves of $X$ is rational polyhedral whenever $c_1(X)$ is ample. For varieties $X$ such that $c_1(X)$ is not ample,…

alg-geom · Mathematics 2007-05-23 Thomas Bauer

We compute the facets of the effective cones of divisors on the blow-up of P^3 in up to five lines in general position. We prove that up to six lines these threefolds are weak Fano and hence Mori Dream Spaces.

Algebraic Geometry · Mathematics 2016-04-21 Olivia Dumitrescu , Elisa Postinghel , Stefano Urbinati

We introduce the moduli stack of pointed curves equipped with effective $r$-spin structures: these are effective divisors $D$ such that $rD$ is a canonical divisor modified at marked points. We prove that this moduli space is smooth and…

Algebraic Geometry · Mathematics 2009-09-29 Alexander Polishchuk

Let M_{7,n} be the (coarse) moduli space of smooth curves of genus 7 with n marked points defined over the complex field. We denote by M^1_{7,n;4} the locus of points inside M_{7,n} representing curves carrying a g^1_4. It is classically…

Algebraic Geometry · Mathematics 2017-09-18 Christian Böhning , Hans-Christian Graf von Bothmer , Gianfranco Casnati

We determine the action of the product of symmetric groups on the cohomology of certain moduli of weighted pointed rational curves. The moduli spaces that we study are of stable rational curves with m+n marked points where the first m…

Algebraic Geometry · Mathematics 2017-10-31 Chitrabhanu Chaudhuri

We compute the class of the effective divisors on $\overline{\mathcal{M}}_{g,n}$, which are set theoretically equal to the locus of moduli points $[C,p_1,\dots ,p_n]$ where $C$ lies on a quadric under the map given by the linear series…

Algebraic Geometry · Mathematics 2018-03-28 İrfan Kadıköylü

We describe the Chow ring with rational coefficients of Mbar_{0,1}(P^n,d) as the subring of invariants of a ring B(Mbar_{0,1}(P^n,d);Q), relative to the action of the group of symmetries S_d. We compute B(Mbar_{0,1}(P^n,d);Q) by following a…

Algebraic Geometry · Mathematics 2007-05-23 Andrei Mustata , Magdalena Anca Mustata

We show that the pseudo-effective cone of divisors of $\overline{M}_{0,n}$ is not polyhedral for $n\geq 8$ by constructing an extremal non-polyhedral ray of the dual cone of moving curves via maps on meromorphic strata of differentials…

Algebraic Geometry · Mathematics 2025-10-30 Scott Mullane

We give a recursive algorithm for computing the character of the cohomology of the moduli space $\Mmb_{0,n}$ of stable $n$-pointed genus zero curves as a representation of the symmetric group $\Sg_n$ on $n$ letters. Using the algorithm we…

Algebraic Geometry · Mathematics 2013-04-29 Jonas Bergström , Satoshi Minabe

We introduce and compute the class of a number of effective divisors on the moduli space of stable maps $\bar M_{0,0}(P^{r},d)$, which, for small d, provide a good understanding of the extremal rays and the stable base locus decomposition…

Algebraic Geometry · Mathematics 2009-05-19 Dawei Chen , Izzet Coskun , Charley Crissman

We introduce arrangements of rational sections over curves. They generalize line arrangements on P^2. Each arrangement of d sections defines a single curve in P^{d-2} through the Kapranov's construction of \bar{M}_{0,d+1}. We show a…

Algebraic Geometry · Mathematics 2011-04-05 Giancarlo Urzua

Let X be a normal projective variety admitting an action of a semisimple group with a unique closed orbit. We construct finitely many rational curves in X, all having a common point, such that every effective one-cycle on X is rationally…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion