It’s 9 a.m. on a Friday in November and yet a steady stream of students is already making its way into Professor of Mathematics Leslie Cheng’s office in Park. The reasons for each visit vary slightly—help with a difficult equation, advice about a course selection, a recommendation for an internship.
“Leslie cares deeply about each of her students and goes to great efforts to support them,” says fellow Professor of Mathematics Lisa Traynor. “In all my years of having her as a colleague, I have never heard her express any frustration at any student. Her patience and belief in the potential of all students is admirable.”
In recognition of her commitment to her students, teaching excellence, and scholarship, Cheng was awarded the Rachel C. Hale Chair at the 2018 Commencement ceremony. To mark this honor, she will be giving a lecture on “My Journey Through Harmonic Analysis” on Thursday, Nov. 29, from 4:30-5:30 p.m. in Room B21 of Carpenter Library. A reception in the London Room will follow the event.
Harmonic analysis is the branch of mathematics that studies the representation of signals or functions as the superposition of basic waves. The basic waves are called “harmonics," hence the name “harmonic analysis." In the past two centuries, it has become a vast subject with applications in areas as diverse as signal processing, quantum mechanics, and neuroscience.
Cheng’s research addresses some of the theoretical aspects of the field. Her results, some jointly with other collaborators, have appeared in various mathematical journals such as Proceedings of the American Mathematical Society, Michigan Mathematical Journal, Studia Mathematica, a Polish mathematics journal founded in 1929 that publishes original papers in English, French, German, or Russian, mainly in functional analysis, abstract methods of mathematical analysis, and probability theory, and Collectanea Mathematica, an international journal of the University of Barcelona and the oldest mathematical journal in Spain.
Cheng’s time at Bryn Mawr didn’t begin at the front of the classroom. In 1988 she came to Bryn Mawr as an undergraduate expecting to major in French or English, but, like so many others, an encounter with now Professor Emeritus of Mathematics Rhonda Hughes changed her academic path.
After an unsuccessful attempt at calculus in high school, Cheng’s guidance counselor told her parents, “that I’d be successful in life as long as I stayed away from math.”
Heeding the counselor’s advice, Cheng met with Hughes to find out what the least challenging courses were that she could take to fulfill the College’s quantitative requirement.
“Meeting Rhonda was a defining moment in my life. She said, ‘I think you should take calculus, you might get it better here than you did in high school,’” recalls Cheng. “I went to her calculus class and it was too good to be true. I actually understood what was going on. Rhonda is such an amazing professor that I started to like math.”
Calculus II followed and before she knew it, Cheng was majoring in math and earned her undergraduate degree as a member of the class of 1992.
After earning her Ph.D. at the University of Pittsburgh, Cheng applied to upward of 40 positions and had several offers, but her heart remained at Bryn Mawr, where an interim position became available.
“My Ph.D. adviser said, ‘You have tenure track job offers,’ but I was young and I wanted to come back to Bryn Mawr.”
Cheng was able to continue to work in adjunct and interim positions until a tenure track position became available in 2002 and has remained at Bryn Mawr since.
“The time has gone by so fast; it seems like yesterday when I started working here.”
In addition to advising math students, Cheng has served as a mentor for the Class of 2019 Boston S.T.E.M. Posse since June 2015.
While this Posse does have several math majors, Cheng says her goal has been to support the students no matter what their major and to try not to steer them toward any particular field.
“I truly believe that our students can accomplish whatever they want in life and the best thing I can do is to provide encouragement and support.”
Math Alumnae on the Influence of Professor Cheng
"Leslie was a friend, mentor and advisor to me throughout my college career. She always put her students' success first and was always there at 11 p.m. to help me and others review before a test the next day or help give me clues to solve a challenging problem set.
"She also went above and beyond the classroom with knowing all of her students' career aspirations and supporting us in that capacity. She motivated many students to apply for jobs and Ph.D. programs they never thought they were qualified for and many proceeded to get these jobs and get into the respective programs." —Ivy Gluck '14, equity analyst at Brandywine Global.
"Leslie was the kind of professor who truly embodied the open door policy, and as a high school math teacher today, a lot of my understanding of how to support students comes from her. She is someone who would bend over backwards to help her students succeed, which sometimes looked like staying at Park into the wee hours of the morning, making sure students got to their classes on time, or even giving me a pair of shoes to borrow when mine broke on the way to her office.
"There was nothing Leslie wouldn't do to make sure students knew she cared about them as a whole human. She made it a point to go to many student events, inquire about students' sleep and work habits, and be flexible when students needed it. I have always admired Leslie's passion for supporting students who came to Bryn Mawr with more gaps in their math backgrounds, and being willing and patient with explaining each problem, step-by-step, whether it was Calc 1 or Abstract Algebra. She was never phased by having 10 or more students crowded in her office, working on different problem sets, often for classes she wasn't teaching.
"It was in these chaotic office hour(s) that I learned the value of collaboration and asking for help when I needed it. Leslie created a space for students to feel like they were capable of anything together, and that is a message and sentiment that has stuck with me in the years since I graduated. Every time I have talked to Leslie post-graduation, I am amazed to see the new responsibilities she is taking on, and how many students she is reaching, both inside and outside of the math department." —Swetha Narasimhan '15, math teacher at The Workshop School.
"Leslie Cheng is the definition of selfless. She puts the needs of her students above all else and is a fierce believer in their potential for success. I was honored to have her as my thesis advisor. Even after graduating she's been a great friend and advocate." —Winnie Hien '12, technical project manager for Ready Education.