The Love Hypothesis by Ali Hazelwood

As a third-year Ph.D. candidate, Olive Smith doesn't believe in lasting romantic relationships but her best friend does, and that's what got her into this situation. Convincing Anh that Olive on her way to a happily ever after was always going to be tough, scientists require proof. So, like any self-respecting woman, Olive panics and kisses the first man she sees. That man is none other than Adam Carlsen, a young hotshot professor, and well-known ass. This is why Olive is positively floored when he agrees to keep her charade a secret and be her fake boyfriend. But when a big science conference goes haywire, their little experiment feels dangerously close to combustion. Olive discovers that the only thing more complicated than a hypothesis on love is putting her own heart under the microscope.