## Geometry & Topology

### Homotopy type of symplectomorphism groups of $S^2{\times}S^2$

Silvia Anjos

#### Abstract

In this paper we discuss the topology of the symplectomorphism group of a product of two 2–dimensional spheres when the ratio of their areas lies in the interval $(1,2]$. More precisely we compute the homotopy type of this symplectomorphism group and we also show that the group contains two finite dimensional Lie groups generating the homotopy. A key step in this work is to calculate the mod 2 homology of the group of symplectomorphisms. Although this homology has a finite number of generators with respect to the Pontryagin product, it is unexpected large containing in particular a free noncommutative ring with 3 generators.

#### Article information

Source
Geom. Topol., Volume 6, Number 1 (2002), 195-218.

Dates
Revised: 11 March 2002
Accepted: 26 April 2002
First available in Project Euclid: 21 December 2017

https://projecteuclid.org/euclid.gt/1513882793

Digital Object Identifier
doi:10.2140/gt.2002.6.195

Mathematical Reviews number (MathSciNet)
MR1914568

Zentralblatt MATH identifier
1023.57021

#### Citation

Anjos, Silvia. Homotopy type of symplectomorphism groups of $S^2{\times}S^2$. Geom. Topol. 6 (2002), no. 1, 195--218. doi:10.2140/gt.2002.6.195. https://projecteuclid.org/euclid.gt/1513882793

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