scholarly journals Classification of optimal quaternary Hermitian LCD codes of dimension $2$

Author(s):  
Keita ISHIZUKA
Keyword(s):  
2006 ◽  
Vol 45 (3) ◽  
pp. 1039-1073 ◽  
Author(s):  
Xi Wu ◽  
Stephen S.‐T. Yau
Keyword(s):  

Author(s):  
Paula Tretkoff

This chapter discusses complex algebraic surfaces, with particular emphasis on the Miyaoka-Yau inequality and the rough classification of surfaces. Every complex algebraic surface is birationally equivalent to a smooth surface containing no exceptional curves. The latter is known as a minimal surface. Two related birational invariants, the plurigenus and the Kodaira dimension, play an important role in distinguishing between complex surfaces. The chapter first provides an overview of the rough classification of (smooth complex connected compact algebraic) surfaces before presenting two approaches that, in dimension 2, give the Miyaoka-Yau inequality. The first, due to Miyaoka, uses algebraic geometry, whereas the second, due to Aubin and Yau, uses analysis and differential geometry. The chapter also explains why equality in the Miyaoka-Yau inequality characterizes surfaces of general type that are free quotients of the complex 2-ball.


Author(s):  
Makoto Araya ◽  
Masaaki Harada ◽  
Ken Saito
Keyword(s):  

Author(s):  
P. A. Shaikhullina ◽  

There are consider the problem of constructing an analytical classification holomorphic resonance maps germs of Siegel-type in dimension 2. Namely, semi-hyperbolic maps of general form: such maps have one parabolic multiplier (equal to one), and the other hyperbolic (not equal in modulus to zero or one). In this paper, the first stage of constructing an analytical classification by the method of functional invariants is carried out: a theorem on the reducibility of a germ to its formal normal form by "semiformal" changes of coordinates is proved. The one-time shift along the saddle node vector field (the formal normal form in the problem of the analytical classification of saddle-node vector fields on a plane) is chosen as the formal normal form.


2015 ◽  
Vol 19 (4) ◽  
pp. 651-792
Author(s):  
Stephen S.-T. Yau ◽  
Mingyi Zhang ◽  
Huaiqing Zuo

2012 ◽  
Vol 45 (22) ◽  
pp. 225201 ◽  
Author(s):  
Yan Wang ◽  
Zhiqi Chen ◽  
Chengming Bai
Keyword(s):  

2022 ◽  
pp. 1-16
Author(s):  
André G. Oliveira

Abstract Given any topological group G, the topological classification of principal G-bundles over a finite CW-complex X is long known to be given by the set of free homotopy classes of maps from X to the corresponding classifying space BG. This classical result has been long-used to provide such classification in terms of explicit characteristic classes. However, even when X has dimension 2, there is a case in which such explicit classification has not been explicitly considered. This is the case where G is a Lie group, whose group of components acts nontrivially on its fundamental group $\pi_1G$ . Here, we deal with this case and obtain the classification, in terms of characteristic classes, of principal G-bundles over a finite CW-complex of dimension 2, with G is a Lie group such that $\pi_0G$ is abelian.


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