Generalized flag structures occur naturally in modern geometry. By extending Stefan's well-known statement on generalized foliations we show that such structures admit distinguished charts. Several examples are included.
We show that the property of having only vanishing triple Massey products in equivariant cohomology is inherited by the set of fixed points of hamiltonian circle actions on closed symplectic manifolds. This result can be considered in a more general context of characterizing homotopic properties of Lie group actions. In particular it can be viewed as a partial answer to a question posed by Allday and Puppe about finding conditions ensuring the "formality" of G-actions.
An -ary Poisson bracket (or generalized Poisson bracket) on the manifold is a skew-symmetric -linear bracket of functions which is a derivation in each argument and satisfies the generalized Jacobi identity of order , i.e.,
We describe a new link between Perelman’s monotonicity formula for the reduced volume and ideas from optimal transport theory.
It is easily seen that the graphs of harmonic conjugate functions (the real and imaginary parts of a holomorphic function) have the same nonpositive Gaussian curvature. The converse to this statement is not as simple. Given two graphs with the same nonpositive Gaussian curvature, when can we conclude that the functions generating their graphs are harmonic? In this paper, we show that given a graph with radially symmetric nonpositive Gaussian curvature in a certain form, there are (up to) four families...
We study the problem of existence of surfaces in R3 parametrized on the sphere S2 with prescribed mean curvature H in the perturbative case, i.e. for H = Ho + EH1, where Ho is a nonzero constant, H1 is a C2 function and E is a small perturbation parameter.