Jean-Marie Duhamel

{{Short description|French mathematician and physicist}} {{Infobox scientist | name = Jean-Marie Constant Duhamel | image = JMC Duhamel.jpg | image_size = | caption = | birth_date = {{birth date|df=y|1797|2|5}} | birth_place = [[Saint-Malo]], [[Ille-et-Vilaine]], France | death_date = {{death date and age|df=y|1872|4|29|1797|2|5}} | death_place = Paris, France | citizenship = | nationality = | fields = [[Mathematics]]<br>[[Physics]] | workplaces = | patrons = | education = | alma_mater = | thesis_title = De l'influence du double mouvement des planètes sur les températures de leurs différents points | thesis_url = https://patrimoine.sorbonne-universite.fr/idurl/1/1639 | thesis_year = 1834 | doctoral_advisor =  | academic_advisors = | doctoral_students = | notable_students = | known_for = [[Derivative of the exponential map|Duhamel's formula]]<br>[[Duhamel's integral]]<br>[[Duhamel's principle]]<br>[[Vibroscope]] | influences = | influenced = | awards = | spouse =  | partner =  | children = | signature =  | signature_alt = | footnotes = }} '''Jean-Marie Constant Duhamel''' ({{IPAc-en|ˌ|dj|uː|ə|ˈ|m|ɛ|l}};<ref>[http://www.dictionary.com/browse/duhamel "Duhamel"]. ''[[Random House Webster's Unabridged Dictionary]]''.</ref> {{IPA|fr|dy.amɛl|lang}}; 5 February 1797 – 29 April 1872) was a [[French people|French]] [[mathematician]] and [[physicist]].

His studies were affected by the troubles of the [[Napoleonic era]]. He went on to form his own school ''École Sainte-Barbe''. [[Duhamel's principle]], a method of obtaining solutions to inhomogeneous linear evolution equations, is named after him. He was primarily a mathematician but did studies on the mathematics of [[heat]], [[mechanics]], and [[acoustics]].<ref>[http://www-history.mcs.st-andrews.ac.uk/Biographies/Duhamel.html John J O'Connor and Edmund F Robertson. The MacTutor History of Mathematics archive]</ref> He also did work in calculus using infinitesimals. Duhamel's theorem for infinitesimals says that the sum of a series of infinitesimals is unchanged by replacing the infinitesimal with its principal part.<ref>H. J. Ettlinger (1922) "A Simple Form of Duhamel's Theorem and Some New Applications", [[American Mathematical Monthly]] 29(7): 239–50</ref>

In 1853 he published about an early recording device he called a [[vibroscope]]. Like other similar devices, the vibroscope was a type of measuring device similar to an [[oscilloscope]], and could not play back the etchings it recorded.<ref>{{cite book |last1=Burgess |first1=Richard James |title=The History of Music Production |date=2014 |publisher= Oxford University Press |isbn=978-0199357178 |url=https://books.google.com/books?id=qMKiAwAAQBAJ | page=3 |accessdate=1 August 2019}}</ref>

== Honours == * [[19617 Duhamel]], [[asteroid]] named after him

==See also== *[[Bogoliubov inner product|Duhamel two-point function]] *[[Convergence tests#Raabe–Duhamel's test|Raabe–Duhamel's test]]

== References == {{reflist}}

{{DEFAULTSORT:Duhamel, Jean Marie Constant}} [[Category:19th-century French mathematicians]] [[Category:Members of the French Academy of Sciences]] [[Category:1797 births]] [[Category:1872 deaths]] [[Category:19th-century French physicists]]