In an effort to remedy Harvard’s relative weakness in a critical field, Harvard has succeeded in luring a star mathematician away from Stanford University to strengthen its own mathematics department.

Horng-Tzer Yau, whom the Harvard Gazette describes as having “harnessed the power of mathematics to analyze and explain physical processes from atomic behavior to the stability of stars,” will officially become a tenured professor here on July 1, at the age of 45 and with several distinguished awards under his belt.

In 2000, Yau, a native of Taiwan, was named one of the 25 annual recipients of the no-strings-attached $500,000 MacArthur Foundation Fellowship—popularly known as the “genius grant”—and has since made important contributions to the study of quantum mechanics, partial differential equations, and mathematical physics.

The battle to hire Yau away from Stanford was a “tough” one, according to Mathematics Department Chair Joseph D. Harris and other faculty both here and in Palo Alto, Calif.

“I have to say I give a lot of credit to the administration, who supported us and basically did whatever it took to get the guy here,” Harris said.

Harvard’s aggressive pursuit of Yau, which comes two years after the University’s unsuccessful bid to attract Yau from New York University, stemmed from the recognition of a long-running weakness in the mathematics department, according to Harris and others.

“He has extremely strong analytical skill in partial differential equations and mathematical physics,” said Shing-Tung Yau, Graustein professor of mathematics. “We need to strengthen this area, and he fit in very well.”

One of Horng-Tzer Yau’s colleagues at Stanford, Professor Rick Schoen, described him as “soft spoken and dynamic.” Another, Stanford Mathematics Department Chair Yakov Eliashberg, said Yau “is a quite reserved person.”

Both professors expressed dismay over the departure of Yau, who did not return multiple requests for comment Friday and yesterday.

“I think he is an outstanding mathematician,” Eliashberg said. “We are certainly happy for Harvard and sorry for ourselves.”

Schoen said that Stanford made every effort to keep Yau.

“I think he just sees Harvard as a big challenge for him, research-wise,” he said.

At Stanford, Yau has taught both graduates and undergraduates, and runs a research seminar that regularly attracts distinguished speakers.

“He generates a lot of activity,” Schoen said. “At any given time he’ll have one or two visitors here who he’s working with.”

Harris said he expects Yau’s first year at Harvard to involve teaching a graduate seminar in the fall and a 100-level mathematics course in the spring.

According to Harris, the hire is part of a process of “replacing people who have retired over the last decade” and raising the number of senior mathematics professors back up to historically higher levels. Along with Yau, the department has also hired away MIT’s Michael J. Hopkins and the University of Chicago’s Dennis Gaitsgory, who both specialize in topology and representational theory. All three will become Harvard professors on July 1.

—Staff writer Anton S. Troianovski can be reached at atroian@fas.harvard.edu.