# Guide to the Ernst D. Hellinger (1883-1950) Papers

Collection Title: | Ernst D. Hellinger (1883-1950) Papers |

Dates: | 1906-1975 |

Identification: | 11/3/19/6 |

Creator: | Hellinger, Ernst, 1883- |

Extent: | 2 Boxes |

Language of Materials: | English |

Abstract: | Hellinger studied integral equations, infinite systems of equations, real functions, and continued fractions. A type of integral he introduced in his dissertation became known as “the Hellinger integral” and the Hilbert-Hellinger theory of forms in infinitely many variables profoundly influenced mathematical analysis. The Ernst D. Hellinger Papers fill one and one-half boxes and are arranged in two categories: teaching files and publications. These are preceded by one folder of biographical materials. |

Acquisition Information: | The Ernst Hellinger Papers came to the Northwestern University Archives on December 5, 1988 as Accession 1088-283, through the courtesy of Zita Hayward, Mathematics Library, Northwestern University. |

Processing Information: | William K. Beatty, December, 1988 |

Separated Materials: | None. |

Conditions Governing Access: | None. |

Related Materials: | Additional biographical information on Hellinger can be found in the Department of Mathematics personnel files: Series 11/3/19/2, Box 12, Folder 5, and 11/3/19/3, Box 4, Folders 18 and 19. |

Repository: | Northwestern University Archives Deering Library, Room 110 1970 Campus Dr. Evanston, IL, 60208-2300 URL: http://www.library.northwestern.edu/archives Email: archives@northwestern.edu Phone: 847-491-3354 |

## Biographical/Historical Information

Ernst Hellinger was born in Striegau, Silesia, on September 30, 1883. After studying at the University of Heidelberg and the University of Breslau, Hellinger took his PhD in mathematics at the University of Gottingen (where he worked with David Hilbert and Franz Klein) in 1907. Hellinger studied integral equations, infinite systems of equations, real functions, and continued fractions.

Hellinger taught at Gottingen (1907-1909), Marburg (1909-1914), and Frankfurt (1914-1935). The Nazis removed him from the faculty at Frankfurt in 1936. He joined the faculty at Northwestern as lecturer in Mathematics in 1939. He became a U.S. citizen in 1944. Promoted to professor in 1945, Hellinger became emeritus in 1949. He died March 28, 1950, in Chicago.

Hellinger studied integral equations, infinite systems of equations, real functions, and continued fractions. A type of integral he introduced in his dissertation became known as “the Hellinger integral” and the Hilbert-Hellinger theory of forms in infinitely many variables profoundly influenced mathematical analysis.

## Scope and Content

The Ernst D. Hellinger Papers fill one and one-half boxes and are arranged in two categories: teaching files and publications. These are preceded by one folder of biographical materials.

The teaching files consist primarily of lecture notes which Hellinger wrote in longhand. The folders of Northwestern lectures and related materials are arranged by course number and, within each folder, chronologically. Lectures given at the Illinois Institute of Technology and the University of Frankfurt on Main comprise one folder each whose contents are arranged chronologically.

The publications include the published version of Hellinger's doctoral dissertation and reprints of nine of his articles.

Addition, Box 2

The addition consists of materials acquired by James Rovnyak in the course of his research on Ernst Hellinger, and spans the years 1914-1975. Folders are arranged in chronological order, retaining the categorization and identification supplied by Professor Rovnyak. The two letters from Max Born relating to the early days of quantum mechanics are of special interest. The remainder of the addition consists of lecture notes, contracts and correspondence relating to Hellinger's time at Northwestern University, notes and drafts of scholarly papers, and an anonymous biographical outline.

The James Gregory project is a scholarly paper prepared by Hellinger and Max Dehn, a contemporary and close friend from his days in Frankfurt. A version of this paper was presented at an International Congress (July 4th-5th, 1938; Edinburgh and St. Andrews) held in honor of the 300th anniversary of the birth of Gregory, a l 7th century Scottish mathematician.

The posthumous documents consist of pieces of correspondence that make reference to Hellinger. Material in German is so noted on the container list.

The 11 folders in this addition were added to the 5 folders in Box 2 of the original series.

## Subjects

### Corporate Name

Northwestern University (Evanston, Ill.). Department of Mathematics

### Personal Name

### Subjects

College teachers--Illinois--Evanston

Mathematics teachers--Illinois--Evanston

Mathematics--Study and teaching (Higher)--Illinois--Evanston