Wegner also spent a period as an assistant at the University of Bonn, and finally at the University of Göttingen. It was at Göttingen that he undertook research for his doctorate, advised by Issai Schur, and on 12 October 1928 he was awarded his doctorate for his 28-page thesis Über die ganzzahligen Polynome, die für unendlich viele Primzahlmoduln Permutationen liefern . The second examiner at the oral examination had been Ludwig Bieberbach. In 1929 he habilitated at the University of Göttingen for Pure Mathematics, Applied Mathematics and Theoretical Astronomy. The following four papers, all published in 1931, were submitted from Göttingen: Ein Satz über auflösbare Polynome vom Primzahlgrad; Charakterisierung der binomischen Körper vom Primzahlgrad; Zur Arithmetik der Polynome; and Zum Vielkörperproblem . During the years 1929-31 at Göttingen, Wegner was Richard Courant's assistant. On 6 April 1931 he was appointed as an ordinary professor at the Technische Hochschule in Darmstadt. The authors of  claim:-
Wegner's appointment to Darmstadt was partially based on false information from him about an alleged position as assistant to the Berlin mathematician Georg Wilhelm Scheffers (1866-1945). What was known in 1931 led to some turmoil, but Wegner's appointment was not prevented.Shortly after his appointment, he submitted three further papers all of which appeared in 1931: Über ein algebraisches Problem; Zur Theorie der linearen Differentialgleichungen; and Über einen Satz von Dickson . In January1932 he submitted the paper Zur Theorie der auflösbaren Gleichungen von Primzahlgrad. I , which he dedicated to "his revered teacher and friend G Herglotz for his birthday". We note that Gustav Herglotz held the chair of Applied Mathematics at Göttingen and was 50 years old on 2 February 1931.
Up to this point we have not mentioned Wegner's political views but we must do so now since they play an important role in the events which took place over the next few years. In 1933 the National Socialist party came to power in Germany. Wegner had been a supporter of this party before this and so for him this promised to help him in his career. Wegner joined the SA (the Sturmabteilung which functioned as the original paramilitary wing of the Nazi Party) in 1933, but there is no evidence he took an active part in SA activities. On 7 April 1933 the Civil Service Law provided the means of removing Jewish teachers from the universities. Richard Courant was forced out of Göttingen in May 1933 and his chair had to be filled. Helmut Hasse was appointed in April 1934 but the authorities, unsure if Hasse was committed to National Socialist policies, tried to appoint someone to a second chair at Göttingen who was a firm Nazi supporter. Wegner was a strong candidate but in the end it was decided that, despite his strong support of the National Socialists, his mathematical ability was not suitable for a chair at Göttingen. Erhard Tornier (1894-1982), an ardent Nazi, was appointed to the second Göttingen chair.
Arthur Rosenthal had been promoted to ordinary professor of mathematics at the University of Heidelberg in 1930 and in 1933 he was also dean in the faculty of mathematics and natural sciences. Because he was Jewish he was forced out by the Nazis and in 1936 he moved to the Netherlands before emigrating to the United States in 1939. The University of Heidelberg sought to fill the vacant chair. First it was offered to Eberhard Hopf, but he turned it down, preferring to go to Leipzig. The chair was then offered to Wegner who accepted it on 19 November 1936. However, the appointment was controversial. The chemist Karl Freudenberg is quoted in :-
[Wegner's] appointment to Rosenthal's chair went through without the knowledge of a portion, and indeed a non-National Socialist portion, of the faculty. ... In a normal appointment process, as was customary prior to National Socialism, Wegner would certainly not have been appointed at Heidelberg.It is true that the Baden Ministry of Culture was particularly keen on appointing Wegner, certainly because of his political views. Herbert Seifert who was also a mathematics professor at Heidelberg, stated in 1947 that Wegner would have had little chance of being appointed to Heidelberg in a properly conducted appointment process. Wilhelm Süss, in a letter written in November 1944, stated that "The scientific achievements of Udo Wegner are highly controversial." These statements seem a harsh judgement on Wegner's mathematical achievements and are no doubt coloured to some extent by his political views. However, they must also be seen in the light of the comments made by Wilhelm Süss about Wegner's character. Süss claimed that Wegner was a pathological liar who was mistrusted and shunned by his colleagues. This is supported by statements in :-
He pursued the habilitation of the mathematician Helmut Joachim Fischer, a keen National Socialist, and indeed in opposition to the recommendation of his colleague Herbert Seifert. Wegner declared that a decree existed according to which inadequate academic performance could be compensated for by political service. ... In the faculty he built his position of power ever more recklessly according to the "Führerprinzip." The operation of the Führerprinzip went so far that he, as it later appeared, misused the authority of his office in that he undertook the granting of doctorates which in every way went against the proper procedures for doctorates and were kept secret from the faculty.The dispute between Wegner and Seifert over Helmut Joachim Fischer's habilitation thesis was the first of several arguments between the two. The next confrontation came in 1938 when Wegner invited Ludwig Bieberbach to lecture in Heidelberg. Bieberbach's lecture, The ethnic roots of science. Types of mathematical creativity, was not on a mathematical topic but on his anti-Semitic "German mathematics" theme. The invitation to Bieberbach to give this lecture was typed above the signatures of Wegner and Seifert. However, Seifert had not signed the invitation and only saw the invitation with his forged signature after the lecture was announced to the Institute in Heidelberg and to neighbouring universities. Seifert did not welcome Bieberbach to Heidelberg, nor did he attend his lecture. Another argument arose over the habilitation of Friedrich Ringleb (1900-1966). Ringleb had been awarded a doctorate by Jena but had made a number of unsuccessful attempts to habilitate at Jena in the 1930s. He published a book 'Mathematical Methods in Biology, especially on genetics and racial research' in 1936. Ringleb then attempted to habilitate at Heidelberg but was rejected by Seifert. However, in January 1940 Seifert made a visit to Braunschweig and, while he was absent, Wegner approved Ringleb's habilitation. Wegner claimed that his approval was given using a law that stated that a lack of scientific achievements could be offset by political merits.
Wegner had written an article in Volume 2 of Deutsche Mathematik in 1937 which was in support of Bieberbach's ideas concerning mathematics and race :-
Wegner stressed that mathematics has epistemological value and is not just playing with symbols. Mathematics is linked to art and music as equal expressions of 'völkisch' qualities. German thought is linked to Greek thought in mathematics, as is the German relationship to "nature". Citations range from Plato and Xenophon to the famous French historian Hippolyte Taine, and on to the "classic" racist writer Houston Stewart Chamberlin, and the contemporaries Vahlen and Lenard. Bieberbach has clearly been a source, though he is not explicitly cited.Through the years leading up to World War II and during the war years, there were very few students at the University of Heidelberg. Wegner tried hard to improve the situation arguing that Heidelberg, the oldest German university, should not fall behind universities like Frankfurt and Tübingen. On 21 January 1941 he was appointed Dean of the Natural Sciences and Mathematics Faculty; a short time later he was promoted to be the deputy to the rector Paul Schmitthenner. He continued to hold both these roles until the end of the war.
Wegner tried to create an aeronautical research institute at Heidelberg in 1943 but despite drawing up ambitious plans nothing came of the idea. Wegner himself was working on applications of function theoretical methods to fluid dynamics, looking at applications of conformal mappings to aeronautical research. Up until 1943 Wegner worked on this on his own but after this time others were added to his team doing work considered important for the war effort. Despite the difficulties and staff shortages, Wegner was able to maintain the range of lectures offered to the mathematics students at Heidelberg. By 1943 Germany was suffering badly through bombing by the Allies but Heidelberg escaped. Wilhelm Blaschke was the professor at Hamburg but, while he was on holiday in the Tyrol with his wife, his house in Hamburg was completely destroyed in a bombing raid. Wegner invited Blaschke to Heidelberg saying he was sorely needed there and could participate in military research. Blaschke was keen to accept but he was forced to return to Hamburg.
On 30 March 1945 Heidelberg was occupied by American troops; the university was closed on the following day. Wegner was arrested at his home on 4 April 1945 and detained, but released in May 1945 because of serious illness. The charges against Wegner were listed, he was charged with criminal acts and held under house arrest. His dismissal from the University of Heidelberg took place on 19 November 1945. After settlement of the charges through the denazification proceedings, Wegner went to France. From 1946 to 1949 he worked at the Office National d'Études et de Recherches Aéronautiques in Paris. He worked as a Gymnasium teacher at the English Institute from 1949 to 1956. Wegner wrote two letters to Richard Courant in 1949 (quoted in ):-
I allow myself to ask this question, because I know that you, dear Herr Courant, always have good advice, for you have helped me in all life situations in the most touching way. ...Wegner wanted to obtain money to expand a school which:-
... aims not only to impart information, but also to stimulate creative thinking and to educate cosmopolitan, well-reared, self-secure, and free-thinking people ... aims at the overcoming of nationalistic narrowness through education to European thinking.As Sanford Segal writes :-
These words were written in 1949 by a man who fifteen years previously had been esteemed as having served the Nazi cause long before 30 January 1933, and were addressed to a forced emigré!Courant replied saying he could not be of any help to Wegner, adding:-
I was interested in learning that you had left your position in France. As a matter of fact, I heard some rumours here that you were considering going even further away.In 1957, when Courant was asked for a reference for Wegner to join an aeronautical institute in Brazil, he highly praised his mathematical abilities and added:-
Undoubtedly you know that he belonged to the over-naive and maybe slightly opportunistic people who joined the Nazis. As a consequence my contacts with him have been discontinued. But I feel that he has amply suffered for his mistake and that his talents and other qualities should be used as much as possible.In 1951 Wegner lectured at the Technische Hochschule in Darmstadt and in 1952 at the Technische Hochschule in Karlsruhe. Only in 1956 did Wegner get a permanent academic position when he was appointed as an Ordinary Professor and Director of the Institute of Applied Mechanics at the University of Saarbrücken. He spent 1965-1966 as a visiting professor at the Technische Hochschule in Aachen, then from 1 October 1966 to 30 September 1970 he was an Ordinary Professor and Director of Institute for Mechanics at the University of Stuttgart. He retired at the end of September 1970 and returned to Heidelberg.
Wegner was elected to the Heidelberg Academy of Sciences in 1941. He remained in the Academy until 1953. He was honoured with the award of an honorary degree from the Technische Hochschule in Karlsruhe in 1964. In 1972, to celebrate his 70th birthday, Beiträge zur Mechanik (Festschrift Udo Wegner) was published by the University of Stuttgart. This contains dedications and eleven articles dedicated to Wegner on his 70th birthday.
Article by: J J O'Connor and E F Robertson