# Jeffrey Lagarias

> American mathematician

**Wikidata**: [Q1686462](https://www.wikidata.org/wiki/Q1686462)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Jeffrey_Lagarias)  
**Source**: https://4ort.xyz/entity/jeffrey-lagarias

## Summary
Jeffrey Lagarias is an American mathematician and computer scientist who serves as a professor at the University of Michigan. He is a member of the National Academy of Sciences and is recognized for his extensive contributions to number theory, cryptography, and computational geometry.

## Biography
- **Born:** November 16, 1949, in Pittsburgh
- **Nationality:** United States
- **Education:** Massachusetts Institute of Technology (MIT)
- **Known for:** Contributions to number theory, cryptography, and the theory of wavelets
- **Employer(s):** University of Michigan (Professor since 2002)
- **Field(s):** Number theory, algebraic number theory, algorithms, cryptography, combinatorics, computational geometry, discrete geometry, dynamical systems, linear programming, and mathematical physics

## Contributions
Jeffrey Lagarias has produced a diverse body of work spanning both theoretical and applied mathematics. His research in number theory and algebraic number theory is complemented by significant work in computer science, particularly in the areas of cryptography and algorithms. In 2014, he was recognized for his contributions to the theory of wavelets and harmonic analysis, as well as his work on interior-point and direct search optimization.

Lagarias has also made notable contributions to geometry. In 2003, he collaborated with Ronald Graham on research regarding Apollonian circle packings, a project that established his Erdős number of 2. His work extends into mathematical physics and dynamical systems, demonstrating a broad interdisciplinary approach. As a professor at the University of Michigan since 2002, he has mentored at least ten doctoral students, including Leo Goldmakher, Elizabeth Chen, and Gene Snyder Kopp, thereby influencing the development of the next generation of mathematical researchers.

## FAQs
### Q: What are Jeffrey Lagarias's primary research interests?
A: Jeffrey Lagarias works across several mathematical disciplines, including number theory, cryptography, computational geometry, and dynamical systems. He is also known for his research into algorithms and the theory of wavelets.

### Q: What professional honors has Jeffrey Lagarias received?
A: He is a member of the National Academy of Sciences and a Fellow of both the American Mathematical Society (AMS) and the Society for Industrial and Applied Mathematics (SIAM).

### Q: Where is Jeffrey Lagarias currently employed?
A: He has been a professor at the University of Michigan since 2002.

## Why They Matter
Jeffrey Lagarias is a significant figure in the mathematical community due to his ability to bridge pure mathematics and practical computational applications. His work in cryptography and algorithms is foundational to secure communication and efficient computing. By advancing the theory of wavelets and optimization, he has provided essential tools for harmonic analysis and industrial sectors. His election to the National Academy of Sciences and his fellowships in major societies like the AMS and SIAM underscore his standing as a leader in his field. Furthermore, his extensive record of doctoral mentorship ensures that his research methodologies and insights continue to impact mathematical scholarship.

## Notable For
*   **National Academy of Sciences:** Elected member of this prestigious organization.
*   **SIAM Fellow (2014):** Recognized for contributions to wavelets, harmonic analysis, and optimization.
*   **AMS Fellow (2012):** Named a Fellow of the American Mathematical Society.
*   **Erdős Number 2:** Established through a 2003 collaboration with Ronald Graham on Apollonian circle packings.
*   **Academic Leadership:** Professor at the University of Michigan for over two decades, supervising numerous doctoral candidates.

## Body

### Academic Background
Jeffrey Lagarias was born on November 16, 1949, in Pittsburgh, Pennsylvania. He completed his higher education at the Massachusetts Institute of Technology (MIT), where he was advised by Harold Stark. 

### Career and Affiliations
Lagarias joined the University of Michigan in 2002, where he holds the position of professor. His academic presence is supported by a strong digital footprint, including a maintained professional website at the University of Michigan and various researcher identifiers such as ORCID and the Mathematics Genealogy Project.

### Research and Fields of Work
Lagarias's research portfolio is exceptionally broad, covering:
*   **Theoretical Mathematics:** Number theory, algebraic number theory, combinatorics, and discrete geometry.
*   **Applied Mathematics:** Cryptography, linear programming, and mathematical physics.
*   **Computational Science:** Algorithms and computational geometry.
*   **Analysis:** Dynamical systems and the theory of wavelets.

### Honors and Professional Societies
His professional standing is marked by several key memberships and awards:
*   **Society for Industrial and Applied Mathematics (SIAM):** Became a Fellow in 2014. His citation specifically notes his work in wavelets, harmonic analysis, and both interior-point and direct search optimization.
*   **American Mathematical Society (AMS):** Named a Fellow in November 2012 (part of the 2013 class).
*   **National Academy of Sciences:** Member.

### Doctoral Students Mentored
During his tenure at the University of Michigan, Lagarias has served as the doctoral advisor for several students, including:
*   Leo Goldmakher
*   Jonathan Bober
*   Elizabeth Chen
*   Benjamin Leonard Weiss
*   Andrey Mikhaylovich Mishchenko
*   William Cole Abram
*   Julian Haasarud Rosen
*   Harry Altman
*   Trung Hieu Ngo
*   Gene Snyder Kopp

## References

1. Integrated Authority File
2. Czech National Authority Database
3. [ORCID Public Data File 2023](https://pub.orcid.org/v3.0/0000-0002-4157-5527/employment/387693)
4. [Source](https://www.siam.org/prizes-recognition/fellows-program/all-siam-fellows?page=2)
5. [Source](http://www.ams.org/fellows_by_year.cgi?year=2013)
6. [Source](http://www.ams.org/news?news_id=1680)
7. Mathematics Genealogy Project
8. International Standard Name Identifier
9. Virtual International Authority File
10. [Source](https://www.siam.org/prizes-recognition/fellows-program/all-siam-fellows)
11. Freebase Data Dumps. 2013
12. CONOR.SI