NORRISTOWN, Pa. — A University of Pennsylvania professor was charged Monday with bludgeoning his wife to death in their suburban kitchen after she told friends she was going to divorce him. Rafael Robb, 56, taught economics at the Ivy League school and is an expert in game theory, the study of how people and governments make decisions by calculating what others might do. Robb told investigators he was in Philadelphia when his wife was killed Dec. 22. But prosecutors doubted his alibi. District Attorney Bruce Castor said the crime scene was arranged to make it look as if Robb's wife,...