Two decades ago, UC Berkeley mathematician Paulo Ney De Souza co-authored a book, *Berkeley Problems in Mathematics*. At about the same time, Felix Gotti was a teenager in Cuba with a hankering for both mathematics and salsa dancing.

Then, De Souza’s book, which defines the kinds of questions someone hoping for a degree in math from Berkeley would need to be able to answer, landed in Gotti’s hands. Dancing and choreography were never quite the same.

After his application to Berkeley as an undergrad was rejected, Gotti finally was accepted to the university where he’d dreamed of doing postgraduate work. This month, he finished his dissertation and earned his Ph.D. in mathematics.

“Dancing With The Stars” will have to wait; Gotti’s off to Austria to spend June, July and August as a postdoctoral researcher in pure mathematics at the University of Graz. He’s back after that to start doing research in math in Gainesville, Fla. with a grant from the National Science Foundation.

Gotti says he owes much of his current life to the excitement he felt when he first read *Berkeley Problems in Mathematics*. If dance and choreography were his life, he could have remained in Cuba. But to pursue his dream of graduating from a world-class university, he had to leave his home country.

“When I first skimmed this book in Cuba, I couldn’t even understand the statement of the problems,” Gotti says. The book was in English, and Gotti only spoke and read Spanish. He needed a friend’s help to translate the text, and it was a frustrating process.

“However, the frustration of not understanding promptly transformed into motivation to learn more about what a top institution referred to as ‘basic college math,’” he says. “Then, I started learning more and more about the Berkeley undergrad program, and the idea of Berkeley and my ideal career dream started subtly merging.”

De Souza, who was a lecturer in astronomy at Berkeley in the 1990s and was director of computing in the Berkeley Department of Mathematics from 1992-2002, still lives in Berkeley doing research, although he hasn’t taught a mathematics class in more than a decade. He says his book, which was co-written with fellow Berkeley alum Jorge Nuno Silva, now at the University of Lisbon, likely was a nightmare for Gotti to work his way through not knowing English.

De Souza says that when he was a student, Berkeley tended to enroll many more students into its postgraduate mathematics program than the school expected to get doctorates. The test that all students had to take winnowed down the field. He says he feels his book, still in print, is a public service for the mathematically minded around the world.

Having it serve as a recruiting tool for Berkeley? De Souza says that’s a new one.

“I’m glad the book is used that way,” he says. “But I never thought of it like that.”

Thus encouraged to head to in pursuit of their educational dream in 2007, Gotti and his wife, Marly Cormar, had to find a way out of Cuba. The authorities there would have turned thumbs-down any attempt to go directly to the United States, so the couple applied for passage to Mexico.

“I think of it as an escape,” Gotti says. “Permission to leave for the U.S. would have been automatically denied. So, we went to Mexico, and once there, we traveled to the border and asked for political asylum. I explained the impossibility of fulfilling our dreams in Cuba and our desires to contribute toward American society as the scientists we hoped to become.”

At the time, getting across the border and receiving asylum was the easy part. Given access to the U.S., they settled in Florida, where Gotti was able to take a free crash course at the University of Florida to learn English while working at a nearby hotel picking up trash and cleaning floors. After 12 months, he was a resident and thus eligible to become a full-time student.

Just not at Berkeley. One year into his University of Florida stint as a math major, Gotti applied to transfer to Berkeley, only to have the university say no. He gave Berkeley another shot as his four years at Florida were winding down. In 2014, Berkeley welcomed him as a graduate student.

In his first two years at Berkeley, dancing and choreography — he was the choreographer for Salsa@Cal, a student club, in 2015 — remained staples of his life, and he continued to skydive, a hobby he picked up in 2011. By 2017, however, mathematics became all-consuming, and his other pursuits had to go on hiatus, although they were never far from his mind.

“Dancing and mathematics both test my perseverance and feed my passion,” Gotti says. “To create choreography, one has to put many pieces together in the same context — people, movement, melodies, clothes, etc., and do it in a synchronized and attractive way. To do it, you have to think outside the box and face the challenge to come up with the right idea.

“This is similar to solving a complex math problem, or doing math research. One has to make concepts, variables and theorems fit together in a very precise way. Most of the time, this is very challenging. That comes with a certain amount of frustration, so you need perseverance. But when perseverance and patience culminate with a successful outcome, whether it’s a beautiful theorem or choreography, then that creates passion.”

Gotti isn’t sure if there will be dancing or skydiving on the agenda in Graz. He’s jumped from airplanes six times and says he’s not sure there needs to be a seventh. What is clear is that he wants to get back to dancing, while pursuing a career in mathematics research and, eventually, teaching.

“Dance is a healthy and joyful activity for me,” he says. “I haven’t danced for more than two years now, but I plan to take it up again. I’ve decided I’m not a skydiver, though. I’m learning to keep far away from open doors of flying airplanes.”