I am doing a project on Hamiltonian group actions on symplectic manifolds, and my supervisor was able to list several good books on Riemannian geometry to start me off, but he didn't know of any single place to learn about Hamiltonian groups. 


I have found some books (even available online from the author!) that come highly recommended, specifically: *Introduction to Symplectic and Hamiltonian Geometry, A. C. da Silva.*


As the title suggests however, this seems to come from more of a geometric standpoint. Which books are recommended that might focus on the group-theory and topology end of this subject? The project description specifically mentions cohomological obstructions, something that I think is related to group cohomology? (At this point I'm getting all of this from Wikipedia...) 


I have had basic, introductory courses in Differential Geometry (in $\mathbb{R}^n$) and in topology (up to calculating the first fundamental group of a topological space). 


Thank you in advance for any input!



Recommended textbooks for Hamiltonian group actions?
The best Book about Hamiltonian action is


[Moment Maps, Cobordisms, and Hamiltonian Group Actions
 Par Victor Guillemin,Yael Karshon,Viktor L. Ginzburg](http://lib.org.by/get/M_Mathematics/MD_Geometry%20and%20topology/MDdg_Differential%20geometry/Ginzburg%20V.L.,%20Guillemin%20V.,%20Karshon%20Y.%20Moment%20maps,%20cobordisms,%20and%20Hamiltonian%20group%20actions%20%28AMS,%202002%29%28ISBN%200821805029%29%28356s%29_MDdg_.pdf)


The second excellent lecture note is from Heckman


[Lecture notes on Geometry of the momentum map, written with Gert Heckman,](http://www.staff.science.uu.nl/~kolk0101/SpringSchool2004/momentum.pdf)


Moreover, from geometric point of view this book is excellent


[Convexity Properties of Hamiltonian Group Actions](http://en.bookfi.org/book/1307294) 
 Victor Guillemin,Reyer Sjamaar


Following note is also good and introductory 


[Hamiltonian group actions, Sara Grundel](http://www.math.nyu.edu/~kessler/teaching/group/Talk4.pdf)


Also the master thesis entitled "[The Momentum Map, Symplectic Reduction and an
Introduction to Brownian Motion](http://math.berkeley.edu/~alanw/pirlmasters.pdf)" which supervised by Alan Weinstein is very good 


And in final if you know french as Francois said , [Structure des systèmes dynamiques](http://www.jmsouriau.com/structure_des_systemes_dynamiques.htm)


