Grichka Yourievitch Bogdanoff and Igor Yourievitch Bogdanoff were French twin brother television presenters, producers, and scientific essayists who, from the 1970s on, presented various subjects in science fiction, popular science, and cosmology. They were involved in a number of controversies, most notably the Bogdanov affair, in which it was alleged the brothers wrote nonsensical advanced physics papers that were nonetheless published in reputable scientific journals.