Robert Brown (Robby) Gardner (February 27, 1939 – May 5, 1998) was an American mathematician who worked on differential geometry, a field in which he obtained several novel results.
He was the author and co-author of three influential books, produced more than fifty papers, eighteen masters students and thirteen Ph.D students.
His 1991 book, Exterior Differential Systems, coauthored with R.
Bryant Robert Bryant, S.
S.
Chern Shiing-Shen Chern, H.
Goldschmidt and P.
Griffiths Phillips Griffiths, is the standard reference for the subject.
Robert Bryant, Duke University's Professor of Mathematics and the president of the American Mathematical Society (2015-2017) was a student of his.He is better known in the United States for his improvements and popularization of the methods of Élie Cartan (most notably, Cartan's equivalence method, an algorithmic procedure for determining if two geometric shapes are different).
The works of Cartan were hard to grasp for most students, and Gardner worked to explain them in more accessible ways.