Aleksandar MilivojevicGraduate student
I am a third-year graduate student, interested mostly in algebraic topology. I think about rational homotopy theory, characteristic classes, and four manifolds. My advisor is Dennis Sullivan. You can find my CV here.
Some short notes (informal)All manifolds are (unless otherwise stated) smooth, closed, and connected. Spaces have the homotopy type of a finite or countable cell complex. Minimal models are in the sense of rational homotopy theory.
Some computations with the Froelicher spectral sequence.
A discussion on almost-complex and stably-almost-complex structures, and the obstructions to such structures in low dimensions. You can find the minimal models of some relevant homogeneous spaces SO(2n)/U(n) here. And believe it or not, not all homogeneous spaces are formal.
The rational homotopy type of the space of almost complex structures on the six-sphere.
A word on cohomologically split fibrations.
Simply connected manifolds of dimension six or less are formal.
A nilmanifold is a torus iff all of its triple Massey products vanish.
Closed Lie groups are rationally products of odd spheres.
A symplectic non-Kaehler complex threefold all of whose odd Betti numbers are even, and an almost-complex four manifold with no complex structure.
The minimal model of the free loop space of a simply connected space, and an application.
The minimal models of the complex Grassmannians G(2,4), G(2,5), G(2,6), G(3.6), and those of CP2#CP2 and CP2#-CP2.
Representing cohomology of low-dimensional manifolds by maps to other manifolds.
The second-to-last Stiefel-Whitney class of a 4k manifold vanishes.
OtherA 1975 paper by Deligne and Sullivan, Complex vector bundles with discrete structure group, translated from French to English. Here you can find the original.
A brief review of the more topologically-oriented chapters in Freed and Uhlenbeck's "Instantons and Four Manifolds".