## Quick Facts

Intro | German mathematician |

A.K.A. | Hermann Amandus Schwarz, Karl Hermann Amandus Schwarz |

Was | Mathematician Educator |

From | Germany |

Type | Academia Mathematics |

Gender | male |

Birth | 25 January 1843, Jerzmanowa, Gmina Jerzmanowa, Głogów County, Lower Silesian Voivodeship |

Death | 30 November 1921, Berlin, Germany (aged 78 years) |

## Biography

**Karl Hermann Amandus Schwarz** (German: [ʃvaʁts]; 25 January 1843 – 30 November 1921) was a German mathematician, known for his work in complex analysis.

## Life

Schwarz was born in Hermsdorf, Silesia (now Jerzmanowa, Poland). He was married to Marie Kummer, who was the daughter to the mathematician Ernst Eduard Kummer and Ottilie née Mendelssohn (a daughter of Nathan Mendelssohn's and granddaughter of Moses Mendelssohn). Schwarz and Kummer had six children.

Schwarz originally studied chemistry in Berlin but Ernst Eduard Kummer and Karl Theodor Wihelm Weierstraß persuaded him to change to mathematics. He received his Ph.D. from the Universität Berlin in 1864 and was advised by Ernst Kummer and Karl Weierstraß. Between 1867 and 1869 he worked at the University of Halle, then at the Swiss Federal Polytechnic. From 1875 he worked at Göttingen University, dealing with the subjects of complex analysis, differential geometry and the calculus of variations. He died in Berlin.

## Work

Schwarz's works include *Bestimmung einer speziellen Minimalfläche*, which was crowned by the Berlin Academy in 1867 and printed in 1871, and *Gesammelte mathematische Abhandlungen* (1890).

Among other things, Schwarz improved the proof of the Riemann mapping theorem, developed a special case of the Cauchy–Schwarz inequality, and gave a proof that the ball has less surface area than any other body of equal volume. His work on the latter allowed Émile Picard to show solutions of differential equations exist (the Picard–Lindelöf theorem).

In 1892 he became a member of the Berlin Academy of Science and a professor at the University of Berlin, where his students included Lipót Fejér, Paul Koebe and Ernst Zermelo. In total, he advised 20 Ph.D students.

His name is attached to many ideas in mathematics, including:

- Additive Schwarz method
- Schwarz alternating method
- Schwarzian derivative
- Schwarz lemma
- Schwarz's list
- Schwarz minimal surface
- Schwarz theorem (also known as Clairaut's theorem)
- Schwarz integral formula
- Schwarz–Christoffel mapping
- Schwarz–Ahlfors–Pick theorem
- Schwarz reflection principle
- Schwarz triangle
- Schwarz triangle map
- Cauchy–Schwarz inequality.