Stable minimal surfaces in 3-manifolds

Meeks-Pérez-Ros conjectured in their article “Stable constant mean curvature surfaces” (2008) the following: if a closed, connected Riemannian 3-manifold N does not admit any closed, embedded minimal surfaces whose two-sided covering is stable, then N is finitely covered by the 3-sphere. Recall that a surface is called minimal if it is a critical point of … Continue reading "Stable minimal surfaces in 3-manifolds"

Manfredo do Carmo 1928-2018

Manfredo do Carmo was a Brazilian mathematician working in differential geometry. 1978 he was an invited speaker at the ICM in Helsinki, and 1971-1973 he was president of the Brazilian Mathematical Society. Besides for his mathematical research he was also known for his textbooks.

Mathematik in der Blütezeit des Islam

Die Wikipedia veranstaltet jährlich einen Schreibwettbewerb (link). Es gibt jeweils einen Jurypreis und einen Publikumspreis, und dieses Jahr ging der Publikumspreis an einen mathematischen Artikel: Mathematik in der Blütezeit des Islam. Ein paar mehr Infos gibt es auch in diesem ScienceBlog: link.

John Roe 1959-2018

John Roe, the founder of coarse index theory, passed away last month after a long fight against cancer. His web page is still online ( http://sites.psu.edu/johnroe/ ) and can be visited to get a glimpse not only of his mathematical work, but also of his personal life and all the things in the world that … Continue reading "John Roe 1959-2018"

Nemmers Prize 2018

The Frederic Esser Nemmers Prize in Mathematics goes this year to Assaf Naor “for his profound work on the geometry of metric spaces, which has led to breakthroughs in the theory of algorithms.”

Snowflakes at infinity

The countless shapes of snowflakes have long raised the curiosity of many scientists, among others the famous Kepler. They have by now been classified by empirical observation into 80 different shapes, but a mathematical explanation for this classification seems to be missing. A striking point about them is that, even though two snowflakes are almost … Continue reading "Snowflakes at infinity"

What’s new on the ArXiv: Ricci flow and diffeomorphism groups of 3-manifolds

A new paper proves the contractibility of the space of constant curvature metrics on all 3-manifolds except possibly real projective space. Bamler, Kleiner: Ricci flow and diffeomorphism groups of 3-manifolds, https://arxiv.org/pdf/1712.06197.pdf The Smale conjecture in its original form asserted that the diffeomorphism group of the 3-sphere deformation retracts onto O(3), the isometry group of its … Continue reading "What’s new on the ArXiv: Ricci flow and diffeomorphism groups of 3-manifolds"

What’s new on the ArXiv: A locally hyperbolic 3-manifold that is not hyperbolic

A preprint with a new example shows that the understanding of infinitely generated Kleinian groups will be more complicated than for the finitely generated ones. Cremaschi: A locally hyperbolic 3-manifold that is not hyperbolic, https://arxiv.org/pdf/1711.11568 By the proofs of hyperbolization and tameness, one knows precisely which irreducible 3-manifolds with finitely generated fundamental groups admit hyperbolic … Continue reading "What’s new on the ArXiv: A locally hyperbolic 3-manifold that is not hyperbolic"