## Kodai Mathematical Journal

- Kodai Math. J.
- Volume 41, Number 3 (2018), 591-619.

### On cobrackets on the Wilson loops associated with flat $\mathrm{GL}(1, \mathbf{R})$-bundles over surfaces

#### Abstract

Let $S$ be a closed connected oriented surface of genus $g \gt 0$. We study a Poisson subalgebra $W_1(g)$ of $C^{\infty}(\mathrm{Hom}(\pi_1(S), \mathrm{GL}(1, \mathbf{R}))/\mathrm{GL}(1, \mathbf{R}))$, the smooth functions on the moduli space of flat $\mathrm{GL}(1, \mathbf{R})$-bundles over $S$. There is a surjective Lie algebra homomorphism from the Goldman Lie algebra onto $W_1(g)$. We classify all cobrackets on $W_1(g)$ up to coboundary, that is, we compute $H^1(W_1(g), W_1(g) \wedge W_1(g)) \cong \mathrm{Hom}(\mathbf{Z}^{2g}, \mathbf{R})$. As a result, there is no cohomology class corresponding to the Turaev cobracket on $W_1(g)$.

#### Article information

**Source**

Kodai Math. J., Volume 41, Number 3 (2018), 591-619.

**Dates**

First available in Project Euclid: 31 October 2018

**Permanent link to this document**

https://projecteuclid.org/euclid.kmj/1540951256

**Digital Object Identifier**

doi:10.2996/kmj/1540951256

**Mathematical Reviews number (MathSciNet)**

MR3870706

**Zentralblatt MATH identifier**

07000586

#### Citation

Nobuta, Moeka. On cobrackets on the Wilson loops associated with flat $\mathrm{GL}(1, \mathbf{R})$-bundles over surfaces. Kodai Math. J. 41 (2018), no. 3, 591--619. doi:10.2996/kmj/1540951256. https://projecteuclid.org/euclid.kmj/1540951256