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#### Mike Kruger

##### Guest

http://news.yahoo.com/s/ap/20051227...JkPLBIF;_ylu=X3oDMTA5aHJvMDdwBHNlYwN5bmNhdA--

KANSAS CITY, Mo. - A professor at the University of Missouri-Columbia is

being recognized for solving a math problem that had stumped his peers for

more than 40 years.

The achievement has landed Steven Hofmann an invitation to speak next spring

at the 2006 International Congress of Mathematicians in Madrid, Spain.

"It is like a baseball player being picked for the all-star team," Hofmann

said of the invitation to the event, which is held every four years.

The problem, known as Kato's Conjecture, applies to the theory of waves

moving through different media, such as seismic waves traveling through

different types of rock. It bears the name of Tosio Kato, a now-deceased

mathematician at the University of California-Berkeley, who posed the

problem in research papers first written in 1953 and again in 1961.

.... the problem began to take over his life in 1996. Until he solved it in

2000, it was the last thing he thought about before he went to bed and the

first thing he thought about when he woke. He spent two to eight hours each

day on the problem, working periodically with several colleagues.

"I could be out for a bike ride, and I would be thinking about it," Hofmann

told The Kansas City Star. "Sometimes I would be doing something, get an

idea and have to stop ... and write it down."