zbMATH — the first resource for mathematics

Examples
Geometry Search for the term Geometry in any field. Queries are case-independent.
Funct* Wildcard queries are specified by * (e.g. functions, functorial, etc.). Otherwise the search is exact.
"Topological group" Phrases (multi-words) should be set in "straight quotation marks".
au: Bourbaki & ti: Algebra Search for author and title. The and-operator & is default and can be omitted.
Chebyshev | Tschebyscheff The or-operator | allows to search for Chebyshev or Tschebyscheff.
"Quasi* map*" py: 1989 The resulting documents have publication year 1989.
so: Eur* J* Mat* Soc* cc: 14 Search for publications in a particular source with a Mathematics Subject Classification code (cc) in 14.
"Partial diff* eq*" ! elliptic The not-operator ! eliminates all results containing the word elliptic.
dt: b & au: Hilbert The document type is set to books; alternatively: j for journal articles, a for book articles.
py: 2000-2015 cc: (94A | 11T) Number ranges are accepted. Terms can be grouped within (parentheses).
la: chinese Find documents in a given language. ISO 639-1 language codes can also be used.

Operators
a & b logic and
a | b logic or
!ab logic not
abc* right wildcard
"ab c" phrase
(ab c) parentheses
Fields
any anywhere an internal document identifier
au author, editor ai internal author identifier
ti title la language
so source ab review, abstract
py publication year rv reviewer
cc MSC code ut uncontrolled term
dt document type (j: journal article; b: book; a: book article)
Moduli spaces of PU(2)-instantons on minimal class VII surfaces with b 2 =1. (English) Zbl 1159.14022

Let S be any class VII surface, that is a compact complex surface with first betti number b 1 (S)=1 and Kodaira dimension kod(S)=-. Assume furthermore that S is minimal, i.e with second Betti number b 2 (S)=1.

The author describes explicitly the moduli space M(S,E,g) of polystable holomorphic structures with det()=K on a rank two vector bundle E with c 1 (E)=c 1 (K) and c 2 (E)=0 with respect to any possible Gauduchon metrics g on S.

In the non algebraic case, it is known that the moduli space of polystable bundles contain non-filtrable elements and this is a major issue to describe these elements. The authors classify these filtrable bundles and show using gauge theory, that only a particular type can exist. Using a deformation argument and the fact that any class VII surface containing a global spherical shell is the degeneration of a blown-up primary Hopf surface, the author shows that the filtrable bundles are actually generic in the moduli space.

The author studies the local structure of the moduli spaces and their boundary. When S is a half or parabolic Inoue surface, M(S,E,g) is always a compact one-dimensional complex disc. In the general case, when S is an Enoki surface, one obtains a complex disc with finitely many transverse self-intersections whose number becomes arbitrarily large when g varies in the space of Gauduchon metrics. Thus, in that case, the number of singularities is unbounded. In particular, there are infinitely many homeomorphism types of moduli spaces although there are only finitely many topological splittings of the underlying vector bundle. Note that these moduli are not complex space. In the last section, the author dertermines non filtrable bundles which leads to a complete description of the entire moduli space.

The paper underlines the differences between the moduli spaces for algebraic surfaces and minimal class VII surfaces, i.e non Kähler nor elliptic surfaces for which some new phenomena appear. Moreover, in the direction of the pioneering work of [A. Teleman, Invent. Math. 162, No. 3, 493–521 (2005; Zbl 1093.32006)], this article is clearly a step further in the classification of class VII surfaces, since some of the methods can be extended to the case b 2 =2. Finally, the paper is well written.

MSC:
14J60Vector bundles on surfaces and higher-order varieties, and their moduli
14J25Special surfaces
57R57Applications of global analysis to structures on manifolds, Donaldson and Seiberg-Witten invariants