Surface braid groups, Finite Heisenberg covers and double Kodaira fibrations
نویسندگان
چکیده
We exhibit new examples of double Kodaira fibrations by using finite Galois covers a product $\Sigma_b \times \Sigma_b$, where $\Sigma_b$ is smooth projective curve genus $b \geq 2$. Each cover obtained providing an explicit group epimorphism from the pure braid $\mathsf{P}_2(\Sigma_b)$ to some Heisenberg group. In this way, we are able show that every $b$ base fibration; moreover, number pairwise non-isomorphic fibred surfaces fibering over fixed at least $\boldsymbol{\omega}(b+1)$, $\boldsymbol{\omega} \colon \mathbb{N} \to \mathbb{N}$ stands for arithmetic function counting distinct prime factors positive integer. As particular case our general construction, obtain real $4$-manifold signature $144$ can be realized as surface bundle $2$, with fibre $325$, in two different ways. This provides (to knowledge) first "double" solution problem Kirby's list low-dimensional topology.
منابع مشابه
Double Kodaira Fibrations
The existence of a Kodaira fibration, i.e., of a fibration of a compact complex surface S onto a complex curve B which is a differentiable but not a holomorphic bundle, forces the geographical slope ν(S) = c 1 (S)/c2(S) to lie in the interval (2, 3). But up to now all the known examples had slope ν(S) ≤ 2 + 1/3. In this paper we consider a special class of surfaces admitting two such Kodaira fi...
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ژورنال
عنوان ژورنال: Annali della Scuola normale superiore di Pisa. Classe di scienze
سال: 2021
ISSN: ['0391-173X', '2036-2145']
DOI: https://doi.org/10.2422/2036-2145.201908_004