Hands-on GitHub Actions (Getting Started with GitHub Actions Workflows)

Our main result is a local-to-global principle for Morse quasigeodesics, maps and actions. As an application of our techniques we show algorithmic recognizability of Morse actions and construct Morse ``Schottky subgroups'' of higher rank semisimple Lie groups via arguments not based on Tits' ping-pong. Our argument is purely geometric and proceeds by constructing equivariant Morse quasiisometric embeddings of trees into higher rank symmetric spaces.

Reposted from the original at https://blog.stephenturner.us/p/positron-assistant-copilot-chat-agent I have a little hobby project I'm working on and I wanted to use the opportunity to fully make the switch to Positron from RStudio. I used Positron here and there when it first came out, but now that it's out of beta and has a more complete feature set (like remote SSH sessions!) I have everything I need to switch and not look back.

We prove results toward classifying compact Lorentz manifolds on which Heisenberg groups act isometrically. We give a general construction, leading to a new example, of codimension-one actions--those for which the dimension of the Heisenberg group is one less than the dimension of the manifold. The main result is a classification of codimension-one actions, under the assumption they are real-analytic.