This page acknowledges friends of the Norbert Wiener Center who have died.

Professor Daniel Sweet

In his tenure at the University of Maryland, Dr. Sweet was heralded for his passion and talent for teaching mathematics, as well as his brilliant research. He passed away tragically in 2004. The Daniel Sweet Memorial Fellowship is made possible by a generous donation from Dr. Sweet's family.
John Benedetto delivered a eulogy at Dr. Sweet's funeral.

From the University of Maryland Diamondback article about Dr. Sweet
after his passing:

Nov 17, 2004
DAN SWEET, 1943-2004
Mathematics professor was a 'standup comic'

Mathematics professor Dan Sweet, 61, died Sunday at Georgetown
Hospital
after suffering a stroke Nov. 10.

Sweet, of Laurel, was known for his passion for teaching and sharp-witted
sense of humor.

For example, university mathematics professor and longtime friend John
Benedetto, remembered visiting Sweet at his home after he had major heart
surgery a few years ago.

"He pointed to his chest after surgery and said, 'Boy, I had a go through
this to get a visit?'" Benedetto recalled. "His sense of humor, probably
in the classroom you didn't see it, but he could've been a standup comic."

Benedetto added Sweet's tough demeanor belied his sensitivity to people's
needs. "He looked tougher than he was."

Gene Harrington, a 1992 journalism alumnus, knew Sweet since he was 7
years old as a neighbor and as "a second dad." Harrington, now 35,
struggled with the journalism school's minimal math requirements. He
attributed his passing MATH 110: Elementary Mathematical Models to Sweet's
informal math tutoring.

"Although he was a genius in his field, he wasn't a math wonk," he said.
"He was just a regular guy blessed with an incredible intellect. He was
able to communicate his genius and that was what made him such an
effective teacher and so fun to be around."

Born in Passaic, N.J., Sweet began his 35-year career with the university
in 1969 after earning his doctorate in mathematics at Brown University,
working for a year at the University of California, Los Angeles, and
marrying his wife, Karen.

"His passion was teaching at the University of Maryland," Karen said. "He
never thought of doing anything else. He could of gone into the industry,
but he received so much satisfaction from teaching."

He won the Dean's Excellence in Teaching Award in 1989, given each year to
one of the 250 faculty in the computer, mathematical and physical sciences
college. While Sweet did publish scholarly research, math department
Chairman Patrick Fitzpatrick said Sweet was a teacher first and a
researcher second.

"He published lots of research articles, but he chose to devote the
majority of his time to his students," he said.

Sweet presented complex math concepts with clarity and simplicity and was,
in the words of math department undergraduate chair Denny Gulick, "the
king" of MATH 410 and 411: Advanced Calculus I and II.

The two courses are among math majors' most challenging, and he recalled
students who put off taking the courses if Sweet wasn't teaching them,
Fitzpatrick said.

Sweet often taught more than 200 students each semester. While Sweet's
family was unable to speak with him after the stroke, Karen took solace in
the fact that her husband collapsed after teaching two of his classes.

"So the last thing he did was something that he loved," she said.

He is survived by his wife Karen, 60, and sons Daniel, 33, of Rockville,
and James, 32, of Chesapeake Beach, Md.

Donations may be sent to 11801 Rockville Pike, Condo #1403, Rockville,
Md., 20852 for the Daniel Sweet Memorial Mathematics Scholarship Fund.

- By senior staff writer Jeremy Hsieh

Frederick C. Williams

Dr. Williams, nuclear physicist and patent
attorney, served as a founding member of the Industrial Advisory
Board for the Norbert Wiener Center. He was a valuable resource,
contributing both legally and scientifically, to the Center
in its first few years. He gave the keynote speech at the
February Fourier Talks in 2006, delivering a lecture titled, "How Universities
Fumble the Ball in the Technology Transfer Game." Dr.
Williams was also a close personal friend. He passed away suddenly
in July 2006, a youthful and vibrant 67.

Dennis Healy passed away in September 2009. He was a Professor
of Mathematics and Applied Mathematics, and an affiliate
Professor of Bioengineering. In addition, Professor Healy
was a Program Manager for the Microsystems Technology Office
of DARPA, and a Research Program Consultant for the National
Institute on Alcohol Abuse and Alcoholism (NIAAA) at NIH.
There is an obituary
for Professor Healy in SIAM news from November 2009.

From left to right: Tim Olson, Radka Turcajova, Dennis, P.T. Topiwala, Geoff Davis, John at SPIE '95 in San Diego

George J Linde

George Linde, born 1941, passed away on January 17, 2012. Linde worked at NRL and earned a MSEE from the University of Maryland in 1971. George made many significant contributions to projects with RADAR.
The NRL has printed an obituary that is available on the NWC Repository of Waveform Design and Software webpage.

Frank W.J. Olver

Frank W.J. Olver, professor emeritus at the Institute for Physical Science and Technology and the Department of Mathematics at the University of Maryland, and faculty appointee of the National Institute of Standards and Technology, passed away in Maryland on April 23, 2013, at the age of 88. A foreign member of the Royal Society of Sciences, Sweden, and a fellow of the UK Institute of Mathematics and its Applications, Frank was renowned for his contributions to asymptotics, numerical analysis, and special functions.

Dr. Olver's full obituary can be found in the June 2013 SIAM News.

Björn D. Jawerth

Björn Jawerth, born November 25, 1952, passed away on Monday, September 2, 2013. Jawerth was a former February Fourier Talks speaker and a brilliant Harmonic Analyst.

Lee Lorch has passed away on February 28th, 2014. He was 98 years old. As a brilliant American mathematician, Lorch fought for equality between blacks and whites, men and women, and all people.
Jean-Pierre Kahane has published a tribute to Lorch in the French publication L'Humanité. Translated version here .
The MAA has also published an article celebrating Lorch.
In addition, the New York Times ran an 1800-word obituary.

Professor Joe Auslander (UMD) organized a special session through the MAA dedicated to Lee's contributions which we include here.

The following video, "Conversations with Lee Lorch" features Lee discussing his experiences with social justice.

Lars Gårding

Swedish mathematician, Lars Gårding, passed away on July 7th, 2014 at age 95. He has made notable contributions to the study of partial differential equations and partial differential operators. He was a professor of mathematics at Lund University in Sweden 1952 - 1984. Together with Marcel Riesz, he was a thesis advisor for Lars Hörmander. He was a dear friend and father figure to the Director of the Norbert Wiener Center. John remembers his remarks in 1985 on the fact that there is no Nobel Prize in Mathematics, see here.

The following is an obituary in the Swedish newspaper Sydsvenskan.

Ying Wang

Ying Wang, our mathematical daughter (Joe Lakey was her thesis adviser), granddaughter,
and sister, died on Wednesday September 23, 2015.
Ying was born on September 11, 1964, and was an Applied Mathematics graduate of
Tianjin Technology University. She was Joe's first Ph.D. student, and graduated from
New Mexico State University in 2001. The title of her dissertation was
"Perturbations of Gabor frames".
At the time of her death, she was an Associate Professor at Georgia Regents University
(formerly Augusta State).
Besides her expertise in harmonic analysis, her range included linear programming,
C++ programming, financial mathematics, bio-mathematics dealing with mechanisms for
renal blood flow control, and the use of frames in a variety of quantum mechanics problems.
Notwithstanding her considerable mathematical skills and contributions, Ying's greatest
contribution was her inspiring humanity. She was kind, caring, gentle, generous, thoughtful,
loving, sensitive -- a gift not only to La Famiglia but to the whole human race.

Picture to the left: Ying with her thesis adviser, Joe Lakey (far left). Her mathematical uncle,
Juan Romero, is beside her to the right. Steve Casey is between Ying and Joe,
and Darrin Speegle is at the far right.

Ying and Chris Heil at the Norbert Wiener Center, 2009. Ying and John at the Norbert Wiener Center, 2009.

Horst Elmar Winkelnkemper

Dedicated to the Memory of Horst Elmar Winkelnkemper (1940-2016), by Dennis Sullivan:

Horst Elmar Winkelnkemper was born in Germany and grew up in Mexico. He attracted the attention of Solomon Lefschetz and
entered graduate school at Princeton in the early 1960s. Elmar was attracted to the robust activity of Bill Browders'
school at the time: constructing and controlling closed manifolds above dimension four via geometric constructions called
surgery. Elmar formulated mantras such as, "A manifold is like a quadratic form," and, "Transversality unlocks the secrets
of the manifold." When these mantras were expressed in lectures at MIT, Is Singer thought "Winkelnkemper" was an fictitious
name for these mathematical insights.

A first result of Elmar was that if the signature of its quadratic form were nonzero, then the degree of a self mapping of a
manifold must be a perfect square. Later his thesis showed that the cobordism groups of manifolds with self diffeomorphisms
had infinitely many linearly independent invariants. Elmar then used diffeomorphisms of manifolds with boundary which are
the identity on the boundary to describe "Open Book" decompositions of closed manifolds of one dimension higher. Elmar and
Bill Thurston used open book decompositions to show that each three-manifold has a contact structure. In the next period
Giroux showed that all contact structures in dimension three are approximated by Elmar's open books. One may speculate
that a signed version of this approximation result could provide a picture of the moving vorticity of three-dimensional
fluid, a currently intractable problem. Elmar's "Graph of a Foliation" clarified the holonomy structure of foliations
allowing non-commutative geometry to enter that area.

In recent work, Elmar defied the logic result that many questions about finitely-presented groups are undecidable.
He showed that each positive definite symmetric integer matrix with determinant one which is not equivalent over the
integers to the identity matrix determines an Artin presentation of a non-trivial perfect group. The proof is a remarkable
combination. Elmar constructs a four-manifold whose boundary would be a homotopy three-sphere if the group were trivial.
This four-manifold, materializing the quadratic form, is impossible by Taubes' augmentation of Donaldson's theory of instantons.
Elmar felt strongly the depth of these connections.

To many Elmar Winkelnkemper passionately shared deep convictions and intuition even in areas outside of his expertise, and
it seemed to this author he could find veins of gold by an uncanny, almost mystical intuition, reminiscent of the great Israel Gelfand.

C. Robert Warner

C. Robert (Bob) Warner was born on August 24, 1931 and died on August 7, 2017 in Toronto.
He was Good Old Bob (GOB) to his closest friends. He was gentle, and civilized, and had a
beautiful sense of humor. He was always dressed with shirt and tie, and probably appeared formal
to casual acquaintances and students, a true misrepresentation of the facts! GOB began
abstract harmonic analysis at UMD. He received his PhD at the University of Rochester under the
direction of William Eberlein, and, after a short stint at the University of Connecticut, he came to UMD as an Assistant Professor in
the early 1960s. By the way, his impersonation of Eberlein was hilarious but, typical of his humanity, it was benign.

GOB's research was in Banach Algebras and spectral synthesis. He had been at Rochester when Rudin, Ken Ross,
and Paul Cohen were on the faculty there, and those had been heady days. I arrived at UMD in 1965 and gave a talk
at John Brace's Functional Analysis seminar. The seminar was held in the evening at Brace's house, with beer afterwards.
I think there was a charge of $.25 for a beer. There was a significant group of functional analysts at UMD then,
including John Horvath, Seymour Goldberg, Adam Kleppner, George Maltese, and Denny Gulick. Maltese was also
an abstract harmonic analyst with a PhD from Hille at Yale, and he became a great friend along with GOB. Well, we were
all friends with a wonderful environment. In any case, my seminar that night was on a little thing that I called Tauberian Translation
Algebras. Afterwards GOB told me that I was close to something called spectral synthesis.

Then the fun began. GOB taught me about spectral synthesis, especially for the Banach algebra
of Haar integrable functions on a locally compact abelian group. GOB was an elegant and deep
mathematician, and usually sought the "right" beautiful proof for his results as well
as what had already been done by others. We were both bachelors then, allowing us to be telephoning at 2 or 3 a.m.
about some mathematical problem. We spent so much time working on various Cantor sets, and
we would also indulge ourselves of various of Canada's distilled beverages -- having a "wee-spot"
GOB used to say. While learning spectral synthesis from GOB I didn't publish a paper for 3 years, something
unheard of in academia today.

Anne (Dr. Anne Woolever Warner) and GOB were a great couple, and Cathy and I were so close with them
before GOB's retirement and return to Toronto.

From left to right: David Joyner, Rod Kerby, David Walnut, Joe Lakey, George Benke

David Lay

David Lay, born March 1st, 1941, passed away on Friday, October 12, 2018. David was Professor Emeritus in the Department of Mathematics at University of Maryland. A profound expositor, educator and researcher, he authored the famous Linear Algebra and its Applications textbook, nearly 40 research articles in functional analysis, and won the Distinguished-Scholar Teacher award at UMD in 1997. A mathematical biography and obituary by Harm Bart is available
here, pages 37-40.

Edoardo Vesentini

Edoardo Vesentini (31 May 1928 – 28 March 2020) was an Italian mathematician and politician who introduced the Andreotti–Vesentini theorem. He was awarded the Caccioppoli Prize in 1962.
Vesentini was born in Rome, and died on 28 March 2020, aged 91.

Richard Wheedon

Richard Wheedon was a professor of mathematics at Rutgers University who made original contributions to Potential Theory, Harmonic Analysis and Partial Differntial Equations. In 2017, the center published a book dedicated to him.