Traian Lalescu (; 12 July 1882 – 15 June 1929) was a
Romanian
mathematician. His main focus was on
integral equations and he contributed to work in the areas of
functional equations,
trigonometric series,
mathematical physics,
geometry,
mechanics,
algebra, and the
history of mathematics.
Life
He went to the
Carol I High School
The Carol I National College ( ro, Colegiul Național Carol I din Craiova) is a high school located in central Craiova, Romania, on Ioan Maiorescu Street. It is one of the most prestigious secondary education institutions in Romania.
Between 1947 ...
in
Craiova
Craiova (, also , ), is Romania's 6th Cities in Romania, largest city and capital of Dolj County, and situated near the east bank of the river Jiu River, Jiu in central Oltenia. It is a longstanding political center, and is located at approximatel ...
, continuing high school in
Roman, and graduating from the
Boarding High School
A boarding school is a school where pupils live within premises while being given formal instruction. The word "boarding" is used in the sense of "room and board", i.e. lodging and meals. As they have existed for many centuries, and now exten ...
in
Iași
Iași ( , , ; also known by other alternative names), also referred to mostly historically as Jassy ( , ), is the second largest city in Romania and the seat of Iași County. Located in the historical region of Moldavia, it has traditionally ...
. After entering the
University of Iași, he completed his undergraduate studies in 1903 at the
University of Bucharest.
He earned his
Ph.D. in Mathematics from the
University of Paris in 1908. His dissertation, ''Sur les
équations de Volterra'', was written under the direction of
Émile Picard. In 1911, he published ''Introduction to the Theory of Integral Equations'', the first book ever on the subject of
integral equations.
After returning to Romania in 1909, he first taught Mathematics at the
Ion Maiorescu Gymnasium in
Giurgiu
Giurgiu (; bg, Гюргево) is a city in southern Romania. The seat of Giurgiu County, it lies in the historical region of Muntenia. It is situated amongst mud-flats and marshes on the left bank of the Danube facing the Bulgarian city ...
. From 1909 to 1910, he was a teaching assistant at the
School of Bridges and Highways, in the department of graphic statistics.
He was a professor at the
University of Bucharest, the
Polytechnic University of Timișoara (where he was the first
rector
Rector (Latin for the member of a vessel's crew who steers) may refer to:
Style or title
*Rector (ecclesiastical), a cleric who functions as an administrative leader in some Christian denominations
*Rector (academia), a senior official in an edu ...
, in 1920), and the
Polytechnic University of Bucharest.
The Lalescu sequence
: