# Camille Jordan

> French mathematician (1838-1922)

**Wikidata**: [Q310755](https://www.wikidata.org/wiki/Q310755)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Camille_Jordan)  
**Source**: https://4ort.xyz/entity/camille-jordan

## Summary
Camille Jordan was a French mathematician (1838–1922) known for his foundational contributions to group theory, particularly in the study of algebraic properties of groups. He was a professor at prestigious institutions like École Polytechnique and Collège de France, shaping modern mathematical research.

## Biography
- Born: January 5, 1838
- Nationality: France
- Education: École Polytechnique, Collège de France
- Known for: Pioneering work in group theory and algebraic structures
- Employer(s): École Polytechnique, Collège de France, Mines ParisTech
- Field(s): Mathematics, group theory, linear algebra, measure theory

## Contributions
Camille Jordan made significant contributions to mathematics, particularly in group theory and algebraic structures. He developed the Jordan normal form, a fundamental concept in linear algebra that decomposes matrices into Jordan blocks, essential for understanding linear transformations. His work on the Jordan curve theorem, which states that a simple closed curve divides the plane into two regions, laid the groundwork for geometric topology. Jordan also formulated the Jordan–Hölder theorem, which ensures the uniqueness of composition series in group theory. Additionally, he contributed to measure theory, extending the notion of size to more complex shapes. His research influenced subsequent mathematicians and remains foundational in modern algebraic and geometric studies.

## FAQs
**What were Camille Jordan's major contributions to mathematics?**
Jordan is best known for his work in group theory, particularly the Jordan–Hölder theorem, and his contributions to linear algebra, including the Jordan normal form. He also made significant advances in geometric topology with the Jordan curve theorem.

**Where did Camille Jordan teach and conduct research?**
He held academic positions at École Polytechnique, Collège de France, and Mines ParisTech, where he mentored students and advanced mathematical research.

**What is the Jordan normal form, and why is it important?**
The Jordan normal form is a matrix decomposition that simplifies linear transformations by breaking them into Jordan blocks, which are essential for solving systems of linear equations and understanding matrix properties.

**How did Camille Jordan influence geometric topology?**
His Jordan curve theorem established that a simple closed curve divides the plane into two distinct regions, forming the basis for modern topological studies of curves and surfaces.

**What awards and recognitions did Camille Jordan receive?**
He was honored with the Poncelet Prize in 1868 and was made an Officer of the Legion of Honour, recognizing his contributions to French science.

## Why They Matter
Camille Jordan's work in group theory and linear algebra laid the groundwork for modern algebraic structures, influencing generations of mathematicians. His Jordan normal form and Jordan curve theorem remain foundational in linear algebra and geometric topology, respectively. As a professor at École Polytechnique and Collège de France, he shaped mathematical education and research, leaving a lasting legacy in both pure and applied mathematics. His contributions to measure theory also extended the field's reach into more complex geometric problems. Jordan's influence persists in academic institutions and research institutions worldwide, where his theorems continue to be taught and applied.

## Notable For
- Pioneer of group theory and algebraic structures
- Developer of the Jordan normal form in linear algebra
- Formulator of the Jordan curve theorem in geometric topology
- Recipient of the Poncelet Prize (1868)
- Officer of the Legion of Honour
- Professor at École Polytechnique, Collège de France, and Mines ParisTech
- Influential in measure theory and geometric topology

## Body
### Early Life and Education
Camille Jordan was born on January 5, 1838, in France. He received his education at École Polytechnique and Collège de France, where he developed a deep understanding of mathematics.

### Academic Career and Affiliations
Jordan held significant academic positions at École Polytechnique, Collège de France, and Mines ParisTech. As a university teacher, he mentored students and advanced mathematical research in France.

### Fields of Study
His work focused on mathematics, particularly group theory, linear algebra, and measure theory. He specialized in algebraic properties of groups and geometric topology.

### Mathematical Contributions
Jordan's research resulted in several named theorems and concepts:
- **Jordan normal form**: A matrix decomposition that simplifies linear transformations by breaking them into Jordan blocks.
- **Jordan curve theorem**: A theorem stating that a simple closed curve divides the plane into two regions.
- **Jordan–Hölder theorem**: A theorem ensuring the uniqueness of composition series in group theory.
- **Jordan measure**: An extension of the notion of size to more complex shapes in measure theory.

### Publications
Jordan's work was published in influential mathematical journals and textbooks, contributing to the development of group theory and linear algebra.

### Professional Memberships
He was a member of learned societies and academies, including the French Academy of Sciences and the Royal Society.

### Awards and Recognition
Jordan received the Poncelet Prize in 1868 and was made an Officer of the Legion of Honour, recognizing his contributions to French science.

### Influence and Legacy
Jordan's work influenced subsequent mathematicians and remains foundational in modern algebraic and geometric studies. His contributions to group theory, linear algebra, and geometric topology continue to shape mathematical research and education.

## References

1. www.accademiadellescienze.it
2. MacTutor History of Mathematics archive
3. BnF authorities
4. Integrated Authority File
5. [French Academy of Sciences](https://www.academie-sciences.fr/archivage_site/academie/membre/)
6. [Source](https://gallica.bnf.fr/ark:/12148/bpt6k3273x/f64.item)
7. Mathematics Genealogy Project
8. [Source](https://gallica.bnf.fr/ark:/12148/bpt6k3273x/f61.item)
9. Czech National Authority Database
10. list of professors at Collège de France
11. [MacTutor History of Mathematics archive](http://www-history.mcs.st-andrews.ac.uk/Biographies/Jordan.html)
12. Complete Dictionary of Scientific Biography
13. Find a Grave
14. [Source](https://es.geneanet.org/cementerio/view/6361242/persons/?individu_filter=JORDAN%2BMarie+Ennemond+Camille)
15. Complete List of Royal Society Fellows 1660-2007
16. Virtual International Authority File
17. CiNii Research
18. Léonore database
19. SNAC
20. Brockhaus Enzyklopädie
21. Gran Enciclopèdia Catalana
22. Proleksis Encyclopedia
23. GeneaStar
24. Freebase Data Dumps. 2013
25. [BnF authorities](http://data.bnf.fr/ark:/12148/cb121089183)
26. CONOR.SI
27. La France savante