I think I heard there is such a theory, but I just can't find reference.So I am asking if there really has such a theory and reference if yes. Thanks firstly!
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A theory of the type you might be talking about is stated in Sullivan's "Theorem 4" in "String topology and sigma models", http://books.google.com/books?hl=en&lr=&id=yuGic0WClQ4C&oi=fnd&pg=PA1&dq=string+topology+and+sigma+models+sullivan&ots=2Oympt_Z4g&sig=W4GOnI6Cn7IjsJEH7x9c8qnnY#v=onepage&q=string%20topology%20and%20sigma%20models%20sullivan&f=false. Whether it is a Theorem is somewhat unclear to me. 

