Collocations for theory - noun

complete, unified
a grand unified theory of the physical forces governing matter

general
coherent
current, modern, new
classical
Keynes misinterpreted the classical theory of interest.

pet
One of her pet theories is that people who restrict their calorie intake live longer.

alternative, conflicting
abstract
His comments are just abstract theory and show little understanding of the realities of the situation.

economic, legal, linguistic, literary, political, scientific, social, etc.
critical
feminist, Marxist, postmodern, structuralist, etc.
Current feminist theory consists of several different trends.
the dominant strand of postmodern theory

chaos, evolutionary, game, number, probability, quantum, string, etc.
conspiracy
a conspiracy theory about the princess's death

set
Each school has its own set of theories.

have, hold
advance, develop, formulate, present, produce, propose, put forward
work on
Police are working on the theory that the murderer was known to the family.

refute, reject
accept
confirm, prove, support
disprove
challenge, test
apply, use

hold sth, suggest sth
explain sth, predict sth
be based on sth

in theory
In theory, these machines should last for ten years.

theory about
He has a theory about why dogs walk in circles before going to sleep.

put (the) theory into practice, theory and practice
the distinction/relationship between theory and practice