Themistocles M. Rassias ( el, Θεμιστοκλής Μ. Ρασσιάς; born April 2, 1951) is a

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

, and a professor at the

National Technical University of Athens The National (Metsovian) Technical University of Athens (NTUA; el, Εθνικό Μετσόβιο Πολυτεχνείο, ''National Metsovian Polytechnic''), sometimes known as Athens Polytechnic, is among the oldest higher education institution ...

(Εθνικό Μετσόβιο Πολυτεχνείο),

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...

. He has published more than 300 papers, 10 research books and 45 edited volumes in research

Mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

as well as 4

textbooks A textbook is a book containing a comprehensive compilation of content in a branch of study with the intention of explaining it. Textbooks are produced to meet the needs of educators, usually at educational institutions. Schoolbooks are textbook ...

in Mathematics (in Greek) for university students. His research work has received more than 18,000 citations according to Google Scholar and more than 5,500 citations according to MathSciNet. His

h-index The ''h''-index is an author-level metric that measures both the productivity and citation impact of the publications, initially used for an individual scientist or scholar. The ''h''-index correlates with obvious success indicators such as winn ...

is 48. He serves as a member of the

Editorial Board The editorial board is a group of experts, usually at a publication, who dictate the tone and direction the publication's editorial policy will take. Mass media At a newspaper, the editorial board usually consists of the editorial page editor, a ...

of several international mathematical journals.

Education

He received his

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

from the

University of California at Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant univ ...

in June 1976. Professor

Stephen Smale Stephen Smale (born July 15, 1930) is an American mathematician, known for his research in topology, dynamical systems and mathematical economics. He was awarded the Fields Medal in 1966 and spent more than three decades on the mathematics facult ...

and Professor

Shiing-Shen Chern Shiing-Shen Chern (; , ; October 28, 1911 – December 3, 2004) was a Chinese-American mathematician and poet. He made fundamental contributions to differential geometry and topology. He has been called the "father of modern differential geome ...

have been his thesis and academic advisors, respectively.

Research

His work extends over several fields of Mathematical Analysis. It includes

Nonlinear Functional Analysis Nonlinear functional analysis is a branch of mathematical analysis that deals with nonlinear mappings. Topics Its subject matter includes: * generalizations of calculus to Banach spaces * implicit function theorems * fixed-point theorems (Br ...

Functional Equations In mathematics, a functional equation is, in the broadest meaning, an equation in which one or several functions appear as unknowns. So, differential equations and integral equations are functional equations. However, a more restricted meaning ...

Approximation Theory In mathematics, approximation theory is concerned with how function (mathematics), functions can best be approximation, approximated with simpler functions, and with quantitative property, quantitatively characterization (mathematics), characteri ...

, Analysis on Manifolds,

Calculus of Variations The calculus of variations (or Variational Calculus) is a field of mathematical analysis that uses variations, which are small changes in functions and functionals, to find maxima and minima of functionals: mappings from a set of functions t ...

Inequalities Inequality may refer to: Economics * Attention inequality, unequal distribution of attention across users, groups of people, issues in etc. in attention economy * Economic inequality, difference in economic well-being between population groups * ...

Metric Geometry In mathematics, a metric space is a set together with a notion of ''distance'' between its elements, usually called points. The distance is measured by a function called a metric or distance function. Metric spaces are the most general settin ...

and their Applications. He has contributed a number of results in the stability of

minimal submanifold In mathematics, a minimal surface is a surface that locally minimizes its area. This is equivalent to having zero mean curvature (see definitions below). The term "minimal surface" is used because these surfaces originally arose as surfaces tha ...

s, in the solution of Ulam's Problem for approximate

homomorphism In algebra, a homomorphism is a structure-preserving map between two algebraic structures of the same type (such as two groups, two rings, or two vector spaces). The word ''homomorphism'' comes from the Ancient Greek language: () meaning "same" ...

s in

Banach spaces In mathematics, more specifically in functional analysis, a Banach space (pronounced ) is a complete normed vector space. Thus, a Banach space is a vector space with a metric that allows the computation of vector length and distance between vector ...

, in the theory of

isometric mapping In mathematics, an isometry (or congruence, or congruent transformation) is a distance-preserving transformation between metric spaces, usually assumed to be Bijection, bijective. The word isometry is derived from the Ancient Greek: ἴσος ' ...

s in

metric space In mathematics, a metric space is a set together with a notion of ''distance'' between its elements, usually called points. The distance is measured by a function called a metric or distance function. Metric spaces are the most general settin ...

s and in

Complex analysis Complex analysis, traditionally known as the theory of functions of a complex variable, is the branch of mathematical analysis that investigates Function (mathematics), functions of complex numbers. It is helpful in many branches of mathemati ...

( Poincaré's inequality and harmonic mappings).

Terminology

(i) Hyers–Ulam–Rassias stability of

functional equations In mathematics, a functional equation is, in the broadest meaning, an equation in which one or several functions appear as unknowns. So, differential equations and integral equations are functional equations. However, a more restricted meaning ...

. (ii) The

Aleksandrov–Rassias problem The theory of isometries in the framework of Banach spaces has its beginning in a paper by Stanisław Mazur and Stanisław M. Ulam in 1932. They proved the Mazur–Ulam theorem stating that every isometry of a normed real linear space onto a norme ...

for isometric mappings.An interview with Themistocles M. Rassias
/ref>

Awards and honors

He has received a number of honors and awards including: * 1977–1978 and 1978–1979, Membership offer from the

School of Mathematics The Department of Mathematics at the University of Manchester is one of the largest unified mathematics departments in the United Kingdom, with over 90 academic staff and an undergraduate intake of roughly 400 students per year (including students ...

of the

Institute for Advanced Study The Institute for Advanced Study (IAS), located in Princeton, New Jersey, in the United States, is an independent center for theoretical research and intellectual inquiry. It has served as the academic home of internationally preeminent scholar ...

Princeton Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the nine ...

, that he could not accept for family reasons. * 1980, Research Associate at the Department of Mathematics of

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

, invited by

Raoul Bott Raoul Bott (September 24, 1923 – December 20, 2005) was a Hungarian-American mathematician known for numerous basic contributions to geometry in its broad sense. He is best known for his Bott periodicity theorem, the Morse–Bott functions whi ...

. * 1980, Visiting Research Professor at the Department of Mathematics of the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

, invited by F. P. Peterson. * 1985–1986, 1986–1987, Teacher of the Year. * 1987, Accademico Ordinario of the Accademia Tiberina, Roma. * 1989–1990, 1990–1991, 1991–1992, Outstanding Faculty Member, University of La Verne, California (Athens Campus). * 1991,

Fellow A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher education ...

of the

Royal Astronomical Society (Whatever shines should be observed) , predecessor = , successor = , formation = , founder = , extinction = , merger = , merged = , type = NGO ...

of London. * 2003, A volume entitled ''Stability of Functional Equations of Ulam-Hyers-Rassias Type'' was dedicated to the 25 years since the publication of Th. M. Rassias' Theorem, edited by S. Czerwik, Hadronic Press Inc., Florida. * 2007, A special volume of th
Banach Journal of Math. Analysis
(Vol. 1, Issues 1 & 2) was dedicated to the 30th Anniversary of Th. M. Rassias' Stability Theorem. * 2008,

Doctor Honoris Causa An honorary degree is an academic degree for which a university (or other degree-awarding institution) has waived all of the usual requirements. It is also known by the Latin phrases ''honoris causa'' ("for the sake of the honour") or ''ad hon ...

(DHC), University of Alba Iulia (Romania). * 2009, Α special issue of the Journal ''Nonlinear Functional Analysis and Applications'' (Vol.14, No.5) was dedicated to the 30th Anniversary of Th. M. Rassias' Stability Theorem. * 2010, Ulam Prize in Mathematics. * 2010,

Honorary Doctorate An honorary degree is an academic degree for which a university (or other degree-awarding institution) has waived all of the usual requirements. It is also known by the Latin phrases ''honoris causa'' ("for the sake of the honour") or ''ad hon ...

, University of Nis (Serbia). * 2011, Α special issue of the ''Journal of Nonlinear Sciences and Applications'' (Vol.4, No.2) was dedicated to the 60th Anniversary of Th. M. Rassias' birth. * 2012, A volume entitle
''Nonlinear Analysis. Stability, Approximation, and Inequalities. In honor of Themistocles M. Rassias on the occasion of his 60th birthday''
Eds., P. M. Pardalos; P. G. Georgiev and H. M. Srivastava was published by

Springer Springer or springers may refer to: Publishers * Springer Science+Business Media, aka Springer International Publishing, a worldwide publishing group founded in 1842 in Germany formerly known as Springer-Verlag. ** Springer Nature, a multinationa ...

, New York, 2012, XXIX+893 pp. * 2016,

(DHC), Valahia University of Targoviste (Romania)
see also
. * 2016, Award for Lifetime Achievements in Mathematics, Conference on Ulam's Type Stability,

Cluj-Napoca ; hu, kincses város) , official_name=Cluj-Napoca , native_name= , image_skyline= , subdivision_type1 = Counties of Romania, County , subdivision_name1 = Cluj County , subdivision_type2 = Subdivisions of Romania, Status , subdivision_name2 ...

, Romania.

Works

* Th. M. Rassias, ''On the stability of the linear mapping in Banach spaces'', Proceedings of the American Mathematical Society 72(1978), 297-300. ranslated in Chinese and published in: ''Mathematical Advance in Translation'', Chinese Academy of Sciences 4 (2009), 382-384.* Th. M. Rassias, ''New characterizations of inner product spaces'', Bulletin des Sciences Mathematiques, 108 (1984), 95-99. * Th. M. Rassias, ''On the stability of functional equations and a problem of Ulam'', Acta Applicandae Mathematicae 62(1) (2000), 23-130. * Th. M. Rassias, ''Major trends in Mathematics''
Newsletter European Math. Soc.
62 (2006), 13-14. Translated in Chinese and published in:Mathematical Advance in Translation, Chinese Academy of Sciences 2 (2008), 172-174. * Th. M. Rassias and J. Brzdek, ''Functional Equations in Mathematical Analysis'',

, New York, 2012. * Th. M. Rassias and J. Simsa
''Finite Sums Decompositions in Mathematical Analysis''

John Wiley & Sons John Wiley & Sons, Inc., commonly known as Wiley (), is an American multinational publishing company founded in 1807 that focuses on academic publishing and instructional materials. The company produces books, journals, and encyclopedias, in p ...

Ltd. (Wiley-Interscience Series in Pure and Applied Mathematics), Chichester, New York, Brisbane, Toronto, Singapore, 1995.

Notes

References

* P. M. Pardalos, P. G. Georgiev and H. M. Srivastava (eds.)
''Nonlinear Analysis. Stability, Approximation, and Inequalities. In honor of Themistocles M. Rassias on the occasion of his 60th birthday''
Springer, New York, 2012. * J.-R. Lee and D.-Y. Shin, ''On the Cauchy-Rassias stability of a generalized additive functional equation'', J. Math. Anal. Appl. 339(1)(2008), 372–383. * A. Najati, ''Cauchy-Rassias stability of homomorphisms associated to a Pexiderized Cauchy-Jensen type functional equation'', J. Math. Inequal. 3(2)(2009), 257-265. * C.-G. Park, ''Homomorphisms between Lie JC*- algebras and Cauchy – Rassias stability of Lie JC*-algebra derivations'', J. Lie Theory, 15(2005), 393–414. * M. Craioveanu, M. Puta and Th.M. Rassias
''Old and New Aspects in Spectral Geometry''

Kluwer Academic Publishers Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing. Originally founded in 1842 in ...

, Dordrecht, Boston, London, 2001. * P. Enflo an
M.S. Moslehian ''An interview with Themistocles M. Rassias''
1 (2007), no. 2, 252-260. (Also translated in Chines

* V. A. Faizev, Th. M. Rassias and P. K. Sahoo, ''The space of

(\psi,\gamma)

-additive mappings on semigroups'',

Transactions of the American Mathematical Society The ''Transactions of the American Mathematical Society'' is a monthly peer-reviewed scientific journal of mathematics published by the American Mathematical Society. It was established in 1900. As a requirement, all articles must be more than 15 p ...

354(11) (2002), 4455-4472. * W. Gautschi, G. Mastroianni and Th. M. Rassias, ''Approximation and Computation: In Honor of Gradimir V. Milovanović'',

, New York, 2011. * D. H. Hyers, G. Isac and Th. M. Rassias
''Stability of Functional Equations in Several Variables''

Birkhäuser Verlag Birkhäuser was a Swiss publisher founded in 1879 by Emil Birkhäuser. It was acquired by Springer Science+Business Media in 1985. Today it is an imprint used by two companies in unrelated fields: * Springer continues to publish science (particu ...

, Boston, Basel, Berlin, 1998. * D. H. Hyers, G. Isac and Th. M. Rassias, ''Topics in Nonlinear Analysis and Applications'',

World Scientific World Scientific Publishing is an academic publisher of scientific, technical, and medical books and journals headquartered in Singapore. The company was founded in 1981. It publishes about 600 books annually, along with 135 journals in various f ...

Publishing Co., Singapore, New Jersey, London, 1997. * S.-M. Jung
''Hyers-Ulam-Rassias Stability of Functional Equations in Mathematical Analysis''
Hadronic Press Inc., Florida, 2001. * G. V. Milovanović, D. S. Mitrinović and Th. M. Rassias
''Topics in Polynomials: Extremal Problems, Inequalities, Zeros''

World Scientific Publishing World Scientific Publishing is an academic publisher of scientific, technical, and medical books and journals headquartered in Singapore. The company was founded in 1981. It publishes about 600 books annually, along with 135 journals in various f ...

Co., Singapore, New Jersey, London, 1994. * P. M. Pardalos, Th. M. Rassias and A. A. Khan
''Nonlinear Analysis and Variational Problems''
Springer Optimization and its Applications 35,

, Berlin, 2010.

External links

Themistocles M. Rassias' Curriculum Vitae
* * Listed i
Highly Cited Greek Scientists
{{DEFAULTSORT:Rassias, Themistocles M. 1951 births Living people 20th-century Greek mathematicians 21st-century Greek mathematicians