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Related papers: Fano Kaleidoscopes and their generalizations

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As a special case of a conjecture by Schwede and Smith, we prove that a smooth complex projective threefold with nef anti-canonical divisor is weak Fano if it is of globally $F$-regular type.

Algebraic Geometry · Mathematics 2024-10-08 Paolo Cascini , Tatsuro Kawakami , Shunsuke Takagi

We first show that quantum resonant states observe particle number conservation and hence are consistent with the probabilistic interpretation of quantum mechanics. We then present for a class of quantum open systems, a resonant-state…

Mesoscale and Nanoscale Physics · Physics 2010-11-04 Naomichi Hatano

We study Fano threefolds with Picard number one equipped with a holomorphic section in $\Omega_V^1(1)$.

Algebraic Geometry · Mathematics 2007-05-23 Priska Jahnke , Ivo Radloff

One of the most intriguing problems, in $q$-analogs of designs and codes, is the existence question of an infinite family of $q$-analog of Steiner systems (spreads not included) in general, and the existence question for the $q$-analog of…

Combinatorics · Mathematics 2017-02-07 Tuvi Etzion

Denote by $E_r$ the $r^{th}$ elementary symmetric polynomial in $\dim V$ variables for a vector space $V$ over an infinite field $\Bbbk$. We describe the rational points on the Fano scheme $F_{d-1}(Z(E_{\dim V-1}))$ of projective…

Algebraic Geometry · Mathematics 2025-08-06 Alexandru Chirvasitu

On a general hypersurface of degree $d\leq n$ in $\mathbb P^n$ or $\mathbb P^n$ itself, we prove the existence of curves of any genus and high enough degree depending on the genus passing through the expected number $t$ of general points or…

Algebraic Geometry · Mathematics 2022-11-22 Ziv Ran

In this paper we consider double covers of the projective space in relation with the problem of extensions of varieties, specifically of extensions of canonical curves to $K3$ surfaces and Fano 3-folds. In particular we consider $K3$…

Algebraic Geometry · Mathematics 2022-05-17 Ciro Ciliberto , Thomas Dedieu

The Fano lineshape arises from the interference of two excitation pathways to reach a continuum. Its generality has resulted in a tremendous success in explaining the lineshapes of many one-dimensional spectroscopies - absorption, emission,…

Chemical Physics · Physics 2017-09-06 Daniel Finkelstein-Shapiro , Felipe Poulsen , Tõnu Pullerits , Thorsten Hansen

We show the existence of $(\epsilon,n)$-complements for $(\epsilon,\Rr)$-complementary projective generalized pairs of Fano type $(X,B+M)$ when either the coefficients of $B$ and $\mu_j$ belong to a finite set or the coefficients of $B$…

Algebraic Geometry · Mathematics 2020-08-18 Guodu Chen , Qingyuan Xue

We present a manifestly geometrically self-dual version of the Fano harmonicity axiom for the projective plane.

Combinatorics · Mathematics 2017-05-02 P. L. Robinson

This work provides a unified formalism for studying difference and (Hasse-) differential algebraic geometry, by introducing a theory of "iterative Hasse rings and schemes". As an application, Hasse jet spaces are constructed generally,…

Algebraic Geometry · Mathematics 2014-02-26 Rahim Moosa , Thomas Scanlon

We explain the Fano peak (an asymmetric resonance peak) as an interference effect involving resonant states. We reveal that there are three types of Fano asymmetry according to their origins: the interference between a resonant state and an…

Mesoscale and Nanoscale Physics · Physics 2015-04-08 Keita Sasada , Naomichi Hatano , Gonzalo Ordonez

In this note, we adapt the Keevash-Sudakov proof of the (Tur\'{a}n) Stability Theorem for the Fano plane to find an explicit dependency between the parameters $\varepsilon$ and $\delta$. This is useful in the solution of a multicolored…

Combinatorics · Mathematics 2020-04-27 Carlos Hoppen , Hanno Lefmann , Knut Odermann

Let X be a smooth, complex Fano 4-fold, and rho(X) its Picard number. If X contains a prime divisor D with rho(X)-rho(D)>2, then either X is a product of del Pezzo surfaces, or rho(X)=5 or 6. In this setting, we completely classify the case…

Algebraic Geometry · Mathematics 2020-07-23 Cinzia Casagrande , Eleonora A. Romano

We show that the set of Fano varieties (with arbitrary singularities) whose anticanonical divisors have large Seshadri constants satisfies certain weak and birational boundedness. We also classify singular Fano varieties of dimension $n$…

Algebraic Geometry · Mathematics 2021-02-22 Ziquan Zhuang

Fano manifolds are basic building blocks in geometry - they are, in a precise sense, atomic pieces of shapes. The classification of Fano manifolds is therefore an important problem in geometry, which has been open since the 1930s. One can…

Algebraic Geometry · Mathematics 2022-10-28 Tom Coates , Alexander M. Kasprzyk

We prove that a Fano variety (with arbitrary singularities) of dimension $n$ in positive characteristic is isomorphic to $\mathbb{P}^n$ if the Seshadri constant of the anti-canonical divisor at some smooth point is greater than $n$ and…

Algebraic Geometry · Mathematics 2020-08-06 Ziquan Zhuang

Intersection numbers for subspace designs are introduced and $q$-analogs of the Mendelsohn and K\"ohler equations are given. As an application, we are able to determine the intersection structure of a putative $q$-analog of the Fano plane…

Combinatorics · Mathematics 2015-10-16 Michael Kiermaier , Mario Osvin Pavčević

In this paper we classify rank two Fano bundles $\cE$ on Fano manifolds satisfying $H^2(X,\Z)\cong H^4(X,\Z)\cong\Z$. The classification is obtained via the computation of the nef and pseudoeffective cones of the projectivization…

Algebraic Geometry · Mathematics 2015-03-10 Roberto Muñoz , Gianluca Occhetta , Luis E. Solá Conde

We consider the problem to determine which blow-ups along subvarieties in products of two projective spaces are log Fano. By describing the nef cones of such blow-ups with special centers, we give a partial classification result. For each…

Algebraic Geometry · Mathematics 2018-09-25 Toru Tsukioka