April 30, 2001

fter pushing forward the mathematical frontiers in the world of theoretical physics for nearly four decades, Kurt Haller, professor of physics, was recently honored with a Festschrift by the respected journal Foundations of Physics, on the occasion of his 70th birthday.

German for "celebration writing," a Festschrift is a volume of scholarly articles written by academic peers as a way to acknowledge and pay tribute to the accomplishments of an esteemed colleague.

"This was a great surprise," says Haller who joined the University in 1964. "I do not claim to be as distinguished as they make me out to be. It's healthy to remain modest about oneself in research."

Haller's colleagues disagree. "In this instance we filled three issues of the journal," notes Munir Islam, professor of physics who served as guest editor for the Festschrift along with UConn colleagues Gerald Dunne and Philip Mannheim and Professor Larry Horwitz of Tel Aviv University. "We ended up with 28 articles," adds Islam, which speaks to the fact that so many people in our field respect Kurt, know his work, and were prepared to contribute."

The roster of physicists previously honored with Festschrifts by Foundations of Physics include a number of Nobel Laureates, including L. de Broglie, E. Schroedinger and P. Dirac, "people who helped to invent quantum mechanics," says Dunne, referring to the rules that govern the behavior of matter and energy on the smallest scales.

Everyday objects in our surroundings are all built up of molecules and atoms, Dunne explains, but atoms themselves have substructure at the nuclear and subnuclear level. Particle physics is a research field devoted to the study of matter at these most innermost levels. Physicists have developed a theory called the Standard Model that describes the known properties of all matter in the universe and how they interact, or exert forces on one another. The Standard Model is an example of what physicists and mathematicians call a "gauge theory". The study of these gauge theories is where Haller has made his biggest contributions.

"The big question," says Dunne, "is whether we can make the transition from theory to practice" and demonstrate that what was shown to be true in theory works in practice as well. "It's one thing to say what a theory is, but Kurt's expertise is to make it work. His gift is to do the technically extremely difficult mathematical calculations that make the theory work consistently."

All science at root is based on asking questions of Nature, says Haller. Noting that theoretical physicists "don't have labs," he says, "we ask those questions in a different way. Nature is built on mathematical laws to an awesome degree of precision, our job is to discover what fruitful correspondence exists between Nature and mathematics."

Haller points to the historical example of the Scotsman James Clerk Maxwell, who in the 1860s formulated a theory of electromagnetism and predicted, among other things, the existence of radio waves.

It wasn't until some 20 years later that a student, Heinrich Rudolf Hertz, given a problem to prove Maxwell wrong, produced the set of equations that not only confirmed Maxwell's electromagnetic theory, but also demonstrated that these waves travel at the velocity of light.

"Maxwell didn't have an inkling" about today's radios and televisions, observes Haller. "He couldn't tell the consequences of his theory until someone contributed the crucial piece of mathematical insight" that enabled basic research to get transferred into applications that have changed our lives.

"One needs to use all the mathematics available to see what a theory says, to see what the equations tell us about Nature," Haller adds. "The most important outgrowths are those outcomes that are totally unforeseen and unforeseeable."

David Bauman