2 papers
math.GT2023
Universal Spin Teichmueller Theory, II. Finite Presentation of P(SL(2,Z))
Robert Penner
In previous works, the universal mapping class group was taken to be the group PPSL(2,Z) of all piecewise PSL(2,Z) homeomorphisms of the unit circle S^1 with finitely many breakpoi…
math.GT2023
Universal Spin Teichmueller Theory, I. The action of P(SL(2,Z)) on Tess^+
Robert Penner
Earlier work took as universal mapping class group the collection PPSL(2,Z) of all piecewise PSL(2,Z) homeomorphisms of the unit circle S^1 with finitely many breakpoints among the…