Looks like it's 9. Bhautik Joshi, first author on this paper, collaborated with Sébastien Ourselin on e.g. [1], and Sébastien Ourselin has an Erdős number of 5

Looks like it's 9. Bhautik Joshi, first author on this paper, collaborated with Sébastien Ourselin on e.g. [1], and Sébastien Ourselin has an Erdős number of 5 [2]. So Stewart's Erdős number is at most 7. Her Bacon number is 2. 'We learned that Kristen Stewart has a Bacon number of two because she and Michael Sheen costarred together in "The Twilight Saga," and Sheen and Bacon starred in "Frost/Nixon."' [3] [1] https://www.researchgate.net/publication/220677921_A_quantitative_assessment_of_approaches_to_mesh_generation_for_surgical_simulation https://www.researchgate.net/publication/220677921_A_quantit... [2] https://zbmath.org/collaboration-distance/?a=ourselin.sebastien&b=erdos.paul https://zbmath.org/collaboration-distance/?a=ourselin.sebast... [3] http://www.mtv.com/news/2442193/bacon-number-google/ http://www.mtv.com/news/2442193/bacon-number-google/