# Good introduction to Morse-Novikov theory?

Morse theory investigates the topology of compact manifolds using critical points of real-valued functions $f\colon\, M\to \mathbb{R}$. Motivated by problems in dynamical systems, Novikov (Multivalued functions and functionals: An analogue of the Morse Theory) began to study Morse theory of closed $1$-forms, a special case of which is circle-valued Morse Theory (the subject of a very nice book by Pajitnov). The key new idea was to use the Novikov ring, a certain ring of formal power series, as a tool to count gradient flow lines of an induced Morse function on a covering space of $M$.

Novikov's ideas have been quite influential, but I have not been able to find a good introductory text on general Morse-Novikov theory just by googling keywords. My interests are in classical differential topology, in low dimensions. The reason that I want such a reference is that I work quite a bit with finite covering spaces (not necessarily abelian covers), and I'm curious as to whether or not Morse-Novikov theory gives me a better intuitive handle on what is happening than just plain old garden-variety Morse theory.

Reference Request: Can anyone recommend/ Does there exist a good introductory text on Morse-Novikov Theory?
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Have you looked at "Topology of closed one-forms" by Farber (AMS, 2003)? –  Mike Usher Mar 26 '12 at 2:49
Didn't know about Farber's book- going to the library to look at it now. –  Daniel Moskovich Mar 26 '12 at 3:31