English

Genus two Lefschetz fibrations with $b^{+}_{2}=1$ and ${c_1}^{2}=1,2$

Geometric Topology 2020-12-23 v3

Abstract

In this article we construct a family of genus two Lefschetz fibrations fn:XθnS2f_{n}: X_{\theta_n} \rightarrow \mathbb{S}^{2} with e(Xθn)=11e(X_{\theta_n})=11, b2+(Xθn)=1b^{+}_{2}(X_{\theta_n})=1, and c12(Xθn)=1c_1^{2}(X_{\theta_n})=1 by applying a single lantern substitution to the twisted fiber sums of Matsumoto's genus two Lefschetz fibration over S2\mathbb{S}^2. Moreover, we compute the fundamental group of XθnX_{\theta_n} and show that it is isomorphic to the trivial group if n=3n = -3 or 1-1, Z\mathbb{Z} if n=2n =-2, and Zn+2\mathbb{Z}_{|n+2|} for all integers n3,2,1n\neq -3, -2, -1. Also, we prove that our fibrations admit 2-2 section, show that their total space are symplectically minimal, and have the symplectic Kodaira dimension κ=2\kappa = 2. In addition, using the techniques developed in \cite{A, AP1, ABP, AP2, AZ, AO}, we also construct the genus two Lefschetz fibrations over S2\mathbb{S}^2 with c12=1,2c_1^{2} = 1, 2 and χ=1\chi = 1 via the fiber sums of Matsumoto's and Xiao's genus two Lefschetz fibrations, and present some applications in constructing exotic smooth structures on small 44-manifolds with b2+=1b^{+}_{2} = 1 and b2+=3b^{+}_{2} = 3.

Keywords

Cite

@article{arxiv.1509.01853,
  title  = {Genus two Lefschetz fibrations with $b^{+}_{2}=1$ and ${c_1}^{2}=1,2$},
  author = {Anar Akhmedov and Naoyuki Monden},
  journal= {arXiv preprint arXiv:1509.01853},
  year   = {2020}
}

Comments

31 pages, 9 figures. In this version, we added more examples (as was mentioned in 2nd version of this preprint, Remark 14). A few references added as well