David Garfinkle^*

• Department of Physics, Oakland University, Rochester, Michigan 48309, USA, and Randall Laboratory of Physics, Michigan Center for Theoretical Physics, University of Michigan, Ann Arbor, Michigan 48109, USA

James Isenberg^†

• Department of Mathematics and Institute for Theoretical Science, University of Oregon, Eugene, Oregon 97403, USA

Jose M. Martin-Garcia^‡

• Laboratoire Univers et Théories, Observatoire de Paris, CNRS, Université Paris Diderot, 92190 Meudon, France, and Institut d’Astrophysique de Paris, Université Pierre et Marie Curie, CNRS, 75014 Paris, France

• ^*garfinkl@oakland.edu
• ^†isenberg@uoregon.edu
• ^‡jose@xact.es