Twistors, Quartics, and del Pezzo Fibrations

نویسندگان

چکیده

We investigate the structure of a variety new Moishezon twistor spaces, by utilizing pluri-half-anti-canonical map from spaces. Each these spaces is bimeromorphic to double covering scroll planes over rational normal curve, and branch divisor cover cut quartic hypersurface. In particular, has pencil Del Pezzo surfaces degree two. Correspondingly, have with big anti-canonical class. The base locus last cycle curves, it an curve on smooth members pencil. These are naturally classified into four types according type singularities divisor, or equivalently, those in also show that hypersurface satisfies strong constraint as result defining polynomial be specific form. Together our previous result, present completes classification whose half-anti-canonical system Twistor larger than been understood for long time before. opposite direction, no example known space smaller

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Nonrational Del Pezzo Fibrations

In this paper we study cubic del Pezzo fibrations f : X → P such that the 3-fold X is smooth and rkPic(X) = 2. These are the examples of smooth 3-fold Mori fibre spaces. The 3-fold X is a divisor in the linear system |3M + nL| on the rational scroll Proj(⊕ i=1 OP1(di)), where n and di are integers, d1 ≥ d2 ≥ d3 ≥ d4 = 0, M is a tautological line bundle, and L is a fibre of the projection to P. ...

متن کامل

Birationally Rigid Del Pezzo Fibrations

In this paper we study del Pezzo fibrations z : X → P1 of degree 1 and 2 such that X is smooth, rk Pic(X) = 2 and K2 X ∈ NE(X). These are examples of smooth birationally rigid 3-fold Mori fibre spaces. We describe all birational transformations of the 3-fold X into elliptic fibrations, fibrations of surfaces of Kodaira dimension zero, and canonical Fano 3-folds. Let X be a smooth 3-fold1 of Pic...

متن کامل

Multiple Fibers of Del Pezzo Fibrations

We prove that a terminal three-dimensional del Pezzo fibration has no fibers of multiplicity ≥ 6. We also obtain a rough classification possible configurations of singular points on multiple fibers and give some examples.

متن کامل

Almost Regular Bundles on Del Pezzo Fibrations

This paper is devoted to the study of a certain class of principal bundles on del Pezzo surfaces, which were introduced and studied by Friedman and Morgan in [10]: The two authors showed that there exists a unique principal bundle (up to isomorphism) on a given (Gorenstein) del Pezzo surface satisfying certain properties. We call these bundles almost regular. In turn, we study them in families....

متن کامل

Real Algebraic Threefolds Iv. Del Pezzo Fibrations

This paper continues the study of the topology of real algebraic threefolds begun in [Kollár97b, Kollár97c, Kollár98a], but the current work is independent of the previous ones in its methodology. The present aim is to understand the topology of the set of real points of threefolds which admit a morphism to a curve whose general fiber is a rational surface. This class of threefolds also appears...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Memoirs of the American Mathematical Society

سال: 2023

ISSN: ['1947-6221', '0065-9266']

DOI: https://doi.org/10.1090/memo/1414