Help the exhausted grad student finish her thesis statement without sounding completely informal. Select the most natural academic collocation.

The professor's new theory on time travel is _____, sparking heated debates and minor shouting matches in the physics department.

The correct answer is highly controversial.

In academic discourse, the adverb "highly" strongly collocates with adjectives like "controversial," "probable," and "effective." We do not typically say "strongly" or "heavily" controversial.