{{Short description|Israeli mathematician (1922–2025)}} {{Infobox scientist | name = | native_name = שמואל אגמון | native_name_lang = he | image = Shmuel Agmon.jpeg | image_size = | caption = Agmon in Nice in 1970 | birth_name = | birth_date = {{birth date|1922|2|2|df=y}} | birth_place = Tel Aviv, Mandatory Palestine | death_date = {{death date and age|2025|3|21|1922|2|2|df=y}} | death_place = Jerusalem, Israel | resting_place = | fields = Analysis, partial differential equations | workplaces = Einstein Institute of Mathematics | alma_mater = Paris-Sorbonne University | thesis_title = | thesis_url = | thesis_year = | doctoral_advisor = Szolem Mandelbrojt | doctoral_students = Eli Shamir | awards = Weizmann Prize (1956)<br>Israel Prize (1991)<br>EMET Prize (2007) | spouse = Galia Yardeni-Agmon<br>Nechama de Shalit }}

'''Shmuel Agmon''' ({{langx|he|שמואל אגמון}}; 2 February 1922 – 21 March 2025) was an Israeli mathematician who was known for his work in analysis and partial differential equations.

==Biography== Shmuel Agmon was born in Tel Aviv, in what was then British-ruled Mandatory Palestine, to Nathan and Chaya Agmon (née Gutman). His father was a prominent writer and his mother was a dentist. Agmon spent the first two years of his life living in Nazareth, where his mother ran a clinic, before the family moved to Jerusalem, where his younger brother Yaakov was born in 1924. He was identified as a gifted child in school, excelling in mathematics and classical literature.<ref name=ams>[https://www.ams.org/journals/notices/202603/rnoti-p201.pdf Shmuel Agmon (1922-2025)]</ref> He was also a Jerusalem youth chess champion.<ref name=ems>[https://ems.press/content/serial-article-files/51844 Shmuel Agmon]</ref> A member of the HaMahanot HaOlim youth movement, Agmon attended high school at the Rehavia Gymnasium and after graduating he joined a hakhshara program at kibbutz Na'an in 1939.

He began his studies in mathematics at the Hebrew University of Jerusalem in 1940. His teachers included Michael Fekete, Abraham Fraenkel, Binyamin Amirà, and Jakob Levitzki. In 1942, Agmon interrupted his studies and enlisted in the British Army, serving in an anti-aircraft unit and then the Jewish Brigade. He served for four years in Palestine, Cyprus, Italy, and Belgium during and immediately after World War II. While on leave in Paris in 1946, he purchased works by French mathematician Édouard Goursat from a local bookstore to resume studying mathematics.<ref>{{cite web|url=http://en.emetprize.org/laureates/exact-sciences/mathematics/prof-shmuel-agmon/|archive-url=https://web.archive.org/web/20190224231502/http://en.emetprize.org/laureates/exact-sciences/mathematics/prof-shmuel-agmon/|url-status=usurped|archive-date=February 24, 2019|website=Emet Prize for Science, Art and Culture|title=Emet Prize Laureates: Prof. Shmuel Agmon|access-date=24 February 2019}}</ref><ref name=ems/><ref name=ams/><ref name=ynet/>

After being discharged from the British Army in 1946, Agmon completed his undergraduate and master's degrees at the Hebrew University and went to France for further studies in 1947. He learned of the passage of the United Nations Partition Plan for Palestine while en route to France by ship in November 1947.<ref name=ynet/> He obtained a PhD from Paris-Sorbonne University in 1949, under the supervision of Szolem Mandelbrojt.<ref>{{cite journal|title=Rice's First Israeli Professor: Shmuel Agmon|first=Melissa|last=Kean|date=Fall 2018|page=3|journal=Branches|volume=14|url=https://jewishstudies.rice.edu/sites/g/files/bxs1211/f/Jewish-Studies-Newsletter-Fall-2018pdf_1.pdf}}</ref> He then went to the United States and worked as a visiting scholar at Rice University from 1950 to 1952 before returning to Jerusalem. He joined the faculty of the Hebrew University of Jerusalem in 1952 and became a full professor in 1959. He was elected to membership in the Israel Academy of Sciences and Humanities in 1964.<ref name=ems/> Agmon retired in 1990 but continued to conduct research.<ref name=ynet/>

In 1947, Agmon married Galia Yardeni, a scholar in the fields of literature and the history of journalism in the Land of Israel. They had three sons, all of whom would become academics: Noam Agmon, a theoretical chemist, Ariel Agmon, a neurobiologist, and Eitan Agmon, a musicologist. Galia died in 1968. He subsequently married Nechama de-Shalit, a psychiatrist and the widow of Amos de-Shalit, in 1972. Nechama died in 1998.<ref name=ems/><ref name=ams/><ref name=ynet>[https://www.ynet.co.il/environment-science/article/h13t0igpye חתן פרס ישראל, המתמטיקאי פרופ' שמואל אגמון, הלך לעולמו בגיל 103]</ref>

Agmon died on 21 March 2025, at the age of 103.<ref>{{cite web |title=האקדמיה אבלה על מותו של חבר האקדמיה פרופ' שמואל אגמון |url=https://www.academy.ac.il/News/NewsItem.aspx?nodeId=658&id=3096 |website=Academy.ac.il |access-date=21 March 2025}}</ref>

==Work== After joining the Hebrew University in 1952, Agmon initially taught a course on partial differential equations. He worked on aspects of elliptic-hyperbolic equations in the 1950s, including the Euler–Tricomi equation. He collaborated with Louis Nirenberg and Avron Douglis in producing two groundbreaking works on elliptic partial differential boundary value problems in 1959 and 1964 that became among the most cited works in mathematical analysis. Agmon's contributions to partial differential equations include Agmon's method for proving exponential decay of eigenfunctions for elliptic operators. In 1965 he published a book on linear boundary value problems for elliptic partial differential equations of general order that became a foundational work in the field. He also taught an advanced undergraduate course on classical analysis. From the mid-1960s, he worked on spectral theory and scattering theory of Schrödinger-type equations, publishing works significant to mathematical physics. Notably, he made precise estimates on the decay of Eigenfunctions of the Schrödinger equation in terms of a metric he defined, which became known as the Agmon metric. His work contributed to the understanding of wave function scattering for short range and long range potentials.<ref>{{cite book|last=Agmon|first=Sh.|title=Lectures on exponential decay of solutions of second-order elliptic equations: bounds on eigenfunctions of ''N''-body Schrödinger operators|series=Mathematical Notes|volume=29|publisher=Princeton University Press|location=Princeton, NJ|isbn=978-0-691-08318-6|year=1982}}</ref><ref name=ams/><ref name=ems/><ref>[https://mathematics.huji.ac.il/shmuel-agmon Shmuel Agmon (1922-2025)]</ref>

==Awards== Agmon was awarded the 1991 Israel Prize in mathematics.<ref>{{cite web|url=http://www.education.gov.il/pras-israel/list4.htm|title=List of Israel Prize recipients|language=he|archive-url=https://web.archive.org/web/20090604190810/http://www.education.gov.il/pras-israel/list4.htm |archive-date=4 June 2009}}</ref> He received the 2007 EMET Prize "''for paving new paths in the study of partial-elliptical differential equations and their problematic language and for advancing the knowledge in the field, as well as his essential contribution to the development of the Spectral Theory and the Distribution Theory of Schrödinger Operators.''"<ref name=emet>{{cite web|url=http://www.emetprize.org/english/Product.aspx?Product=22&Year=2007|website=Emet Prize for Science, Art and Culture|archive-url=https://archive.today/20130414174246/http://www.emetprize.org/english/Product.aspx?Product=22&Year=2007|archive-date=14 April 2013|access-date=17 September 2011|url-status=usurped|title=Prof. Shmuel Agmon}}</ref> He has also received the Weizmann Prize and the Rothschild Prize.<ref name=emet/> In 2012, he became a fellow of the American Mathematical Society.<ref>{{cite web|url=https://www.ams.org/profession/fellows-list|title=List of Fellows of the American Mathematical Society|access-date=3 November 2012|website=American Mathematical Society}}</ref>

==Selected works== *{{cite journal|title=Functions of exponential type in an angle and singularities of Taylor series|journal=Trans. Amer. Math. Soc.|year=1951|volume=70|issue=3|pages=492–508|mr=0041222|doi=10.1090/s0002-9947-1951-0041222-5|last1=Agmon|first1=Shmuel|doi-access=free}} *with Lipman Bers: {{cite journal|title=The expansion theorem for pseudo-analytic functions|journal=Proc. Amer. Math. Soc.|year=1952|volume=3|issue=5|pages=757–764|mr=0057349|doi=10.1090/s0002-9939-1952-0057349-4|last1=Agmon|first1=Shmuel|last2=Bers|first2=Lipman|doi-access=free}} *{{cite journal|title=Complex variable Tauberians|journal=Trans. Amer. Math. Soc.|year=1953|volume=74|issue=3|pages=444–481|mr=0054079|doi=10.1090/s0002-9947-1953-0054079-5|last1=Agmon|first1=Shmuel|doi-access=free}} *{{cite journal|title=Maximum theorems for solutions of higher order elliptic equations|journal=Bull. Amer. Math. Soc.|year=1960|volume=66|issue=2|pages=77–80|mr=0124618|doi=10.1090/s0002-9904-1960-10402-8|last1=Agmon|first1=Shmuel|doi-access=free}} *{{cite book|title=Lectures on elliptic boundary value problems|publisher=Van Nostrand|year=1965|no-pp=yes|pages=iii+291 p}}; {{cite book|title=2nd edition|publisher=AMS Chelsea Pub.|year=2010|isbn=978-0-8218-4910-1}}<ref>{{cite web|author=Berg, Michael|date=March 18, 2010|url=https://maa.org/press/maa-reviews/lectures-on-elliptic-boundary-value-problems |title=review of ''Lectures on Elliptic Boundary Value Problems'' by Shmuel Agmon|website=MAA Reviews, Mathematical Association of America (MAA)}}</ref> *{{cite book|title=Unicité et convexité dans les problèmes différentiels|publisher=Presses de l'Université de Montréal|year=1966|no-pp=yes|pages=156 p}} *{{cite book|title=Spectral properties of Schrödinger operators and scattering theory|publisher=Scuola normale superiore di Pisa|year=1975}} *{{cite book|title=Lectures on exponential decay of solutions of second-order elliptic equations: bounds on eigenfunctions of N-body Schrödinger operators|publisher=Princeton University Press|year=1982|isbn=978-0-691-08318-6}}<ref>{{cite journal|author=Deift, Percy|author-link=Percy Deift|title=Review: ''Lectures on exponential decay of solutions of second-order elliptic equations: bounds on eigenfunctions of N-body Schrödinger operators'', by Shmuel Agmon|journal=Bull. Amer. Math. Soc. (N.S.)|year=1985|volume=12|issue=1|pages=165–169|url=https://www.ams.org/journals/bull/1985-12-01/S0273-0979-1985-15332-7/S0273-0979-1985-15332-7.pdf|doi=10.1090/s0273-0979-1985-15332-7|doi-broken-date=13 September 2025 |doi-access=free}}</ref>

==See also== * Agmon's inequality

==References== {{Reflist}}

==External links== {{commons category|Shmuel Agmon}} * {{MathGenealogy|id=9347}} * {{cite journal|title=Shmuel Agmon (1922–2025)|journal=Notices of the American Mathematical Society|date=March 2026|volume=73|issue=3|pages=201–209|url=https://www.ams.org/journals/notices/202603/rnoti-p201.pdf}}

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{{DEFAULTSORT:Agmon, Shmuel}} Category:1922 births Category:2025 deaths Category:20th-century Israeli mathematicians Category:21st-century Israeli mathematicians Category:Fellows of the American Mathematical Society Category:Einstein Institute of Mathematics alumni Category:Academic staff of the Hebrew University of Jerusalem Category:Israel Prize in mathematics recipients Category:Mathematical analysts Category:Members of the Israel Academy of Sciences and Humanities Category:Paris-Sorbonne University alumni Category:Partial differential equation theorists Category:Rice University faculty Category:Israeli men centenarians Category:Weizmann Prize recipients Category:Rehavia Gymnasium alumni Category:Academics from Tel Aviv Category:Israeli Ashkenazi Jews Category:Hebrew University of Jerusalem alumni Category:Mandatory Palestine military personnel of World War II