The phrase "new theory" refers to a fresh idea or concept that explains a particular subject or problem. It is a recently developed explanation that provides a new perspective or understanding of something. Full definition
But researchers still do not know what dark matter actually is, and some have come up with new theories of gravity to explain the galaxy observations. (newscientist.com)
But recently, an interesting new theory on cloud formation has emerged. (climate-skeptic.com)
He believes that new theories about how to interpret texts have wrongly led us to think we can get rid of important elements of traditional theological education. (religion-online.org)