Received February 8th 2018. Published online March 26th 2019.
Abstract: We give explicit formulae for a differential graded Lie algebra (DGLA) model of the triangle which is symmetric under the geometric symmetries of the cell. This follows the work of Lawrence-Sullivan on the (unique) DGLA model of the interval and of Gadish-Griniasty-Lawrence on an explicit symmetric model of the bi-gon. As in the case of the bi-gon, the essential intermediate step is the construction of a symmetric point. Although in this warped geometry of points given by solutions of the Maurer-Cartan equation and lines given by a gauge transformation by Lie algebra elements of grading zero, the medians of a triangle are not concurrent, various other geometric constructions can be carried out. The construction can similarly be applied to give symmetric models of arbitrary $k$-gons.
Affiliations: Itay Griniasty, Weizmann Institute of Science, Rehovot, Israel, e-mail: itay.griniasty@weizmann.ac.il; Ruth Lawrence, Hebrew University of Jerusalem, Israel, e-mail: ruthel@ma.huji.ac.il