An estimate for the measure theoretic entropy of geodesic flows

A new proof and a generalization of the Osserman-Sarnak estimate for the measure theoretic entropy of geodesic flows is presente

Counting Berg partitions

We call a Markov partition of a two dimensional hyperbolic toral automorphism a Berg partition if it contains just two rectangles. We describe all Berg partitions for a given hyperbolic toral automorphism. In particular there are exactly (k + n + l + m)/2 nonequivalent Berg partitions with the same connectivity matrix (k, l, m, n)

What living mathematicians?

Moja wypowiedź jest ,,styczna'' do dyskusji o matematyce stosowanej. Nawiązuję w niej do opinii prof. Białynickiego-Biruli(2014) o wadze nauczania matematyki. Mam nadzieję dowiedzieć się od Was o nauczaniu wyższej matematyki nie-matematyków w Waszej uczelni. Widzę w tej sprawie wielkie zagrożenie dla utrzymania poziomu, i zakresu, badań matematycznych w Polsce.My statement is "tangent" to the discussion of applied mathematics. I refer to the opinion of the prof. Bialynicki-Birula (2014) about the importance of teaching mathematics. I hope to learn from you about the teaching of higher mathematics non-mathematicians in your university. I see this on a big threat to the maintenance of the level and scope of mathematical research in Poland

W-flows on Weyl manifolds and Gaussian thermostats

A relation between Weyl connections and Gaussian thermostats is exposed and exploited. 2000 Mathematics Subject Classification: 37D, 53C, 70K, 82C05. 1