Professor of Physics Nelson Christensen, along with research associate Marie Anne Bizouard (on sabbatical from the University of Paris-South), Tomoki Isoagai (Carleton Class of 2010), Greg Ely (Carleton Class of 2008), and Santiago Caride (Carleton Class of 2008), are the co-authors of an important paper recently published in Nature Magazine entitled "An Upper Limit on the Amplitude of Stochastic Gravitational-Wave Background of Cosmological Origin."

This investigation by the LIGO (Laser Interferometer Gravitational-Wave Observatory) Scientific Collaboration and the Virgo Collaboration has significantly advances our understanding the early evolution of the universe. 

This achievement is particularly important because typically undergraduates do not appear as co-authors on LIGO-Virgo papers. However, the contributions of the Carleton students were so significant that they were added to the author list. Christensen has been working on the topic of measuring the cosmologically produced gravitational wave background since his MIT PhD thesis in 1990.