We consider the Markoff spectrum on the Hecke group. The Markoff spectrum on H4 is known as the Markoff spectrum of index 2 sublattices by Vulakh and the Markoff spectrum of 2-minimal forms or C-minimal forms by Schmidt, who characterized the…
Eventi
Continued fraction expansions of algebraic power series over a finite field – Yann Bugeaud (Université de Strasbourg)
Almost nothing is known on the continued fraction expansion of an algebraic real number of degree at least three. The situation is different over the field of power series Fp((x−1)), where p is a prime number. For instance, there are algebraic power…
First-order aspects of Coxeter groups – Gianluca Paolini (Università di Torino)
We will talk about recent advancement on the model theory of Coxeter groups. We will focus in particular on affine Coxeter groups and on Droms right-angled Coxeter groups. These investigations lead to a general model-theoretic analysis of…
Irrational numbers and where to find them – Simon Kristensen (Aarhus University)
While all but countably many real numbers are irrational (and even transcendental), it is preciously difficult to decide whether this is the case for concrete real numbers, unless some special reason is apparent. For instance, we all know…
Exotic 4-manifolds with signature zero – R. Inanç Baykur (University of Massachusetts Amherst)
We are going to talk about our recent construction of small symplectic 4-manifolds with signature zero, which include the smallest closed…
A class of locally inhomogeneous complete quaternionic Kähler manifolds – Alejandro Gil-García (Universität Hamburg)
We prove that the one-loop deformation of any quaternionic Kähler manifold in the class of c-map spaces is locally inhomogeneous…