# Caucher Birkar

**Caucher Birkar** (Kurdish: کۆچەر بیرکار/Koçer Bîrkar, lit. 'migrant mathematician'; born **Fereydoun Derakhshani** (Persian: فریدون درخشانی); July 1978, in Marivan County, Kurdistan Province, Iran) is a UK-based Iranian Kurdish mathematician and a professor at the University of Cambridge.

Caucher Birkar | |
---|---|

Born | Fereydoun Derakhshani ^{[1]}^{[2]}1978 (age 40–41) |

Citizenship | Iran, Britain |

Alma mater | University of Tehran University of Nottingham |

Children | 1 |

Awards | Leverhulme Prize (2010) Prize of the FSMP (2010) AMS Moore Prize (2016) Fields Medal (2018) |

Scientific career | |

Fields | |

Institutions | University of Cambridge |

Thesis | Topics in Modern Algebraic Geometry (2004) |

Doctoral advisor | |

Influences | elder brother^{[3]} |

Website | Caucher Birkar Website |

Birkar is an important contributor to modern birational geometry.^{[4]} In 2010 he received the Leverhulme Prize in mathematics and statistics for his contributions to algebraic geometry,^{[5]} and in 2016, the AMS Moore Prize for the article "Existence of minimal models for varieties of log general type", *Journal of the AMS* (2010) (joint with P. Cascini, C. Hacon and J. McKernan).^{[6]} He was awarded the Fields Medal in 2018, "for his proof of boundedness of Fano varieties and contributions to the minimal model problem".^{[7]}

## Contents

## Early life and educationEdit

Birkar is an ethnic Iranian Kurd, and was born in 1978 in Marivan County, Kurdistan Province, Iran, on a subsistence farm, and raised during the Iran-Iraq War.^{[8]} He studied mathematics at the University of Tehran where he received his bachelor's degree. He was awarded the third prize in the International Mathematics Competition for University Students in 2000 ^{[9]} and, shortly after, while still studying in the University, relocated to the UK as a refugee and asked for political asylum.^{[10]} In 2001–2004 Birkar was a PhD student at the University of Nottingham. In 2003 he was awarded the Cecil King Travel Scholarship by the London Mathematical Society as the most promising PhD student.^{[11]}

Upon emigrating to the UK he changed his name to Caucher Birkar, which means "migrant mathematician" in Kurdish.^{[12]}

## ResearchEdit

Together with Paolo Cascini, Christopher Hacon and James McKernan, Birkar settled several conjectures including existence of log flips, finite generation of log canonical rings, and existence of minimal models for varieties of log general type, building upon earlier work of Vyacheslav Shokurov and of Hacon and McKernan.^{[13]}

In the setting of log canonical singularities, he proved existence of log flips along with key cases of the minimal model and abundance conjectures. (This was also proved independently by Hacon and Chenyang Xu.)^{[14]}

In a different direction, he studied the old problem of Iitaka on effectivity of Iitaka fibrations induced by pluri-canonical systems on varieties of non-negative Kodaira dimension. The problem consists of two halves: one related to general fibres of the fibration and one related to the base of the fibration. Birkar and Zhang co-solved the second half of the problem, hence essentially reducing Iitaka's problem to the special case of Kodaira dimension zero.^{[15]}

In more recent work, Birkar studied Fano varieties and singularities of linear systems. He proved several fundamental problems such as Shokurov's conjecture on boundedness of complements and Borisov–Alexeev–Borisov conjecture on boundedness of Fano varieties.^{[16]}^{[17]} In 2018, Birkar was given the Fields Medal for his Fano varieties and his other contributions the minimal model problem.^{[7]} In a video made available by the Simons Foundation, Birkar expressed hope that his Fields Medal will put “just a little smile on the lips” of the world’s estimated 40 million Kurds.^{[18]} Birkar's Fields Medal was stolen on the same day it was awarded to him.^{[19]} In a special ceremony at ICM 2018, Birkar was presented with a replacement medal.^{[20]}

Birkar is also active in the field of birational geometry over fields of positive characteristic. His work together with work of Hacon-Xu nearly completes the minimal model program for 3-folds over fields of characteristic at least 7.^{[21]}

## AwardsEdit

- 2010 Leverhulme Prize in mathematics and statistics for "his outstanding contributions to fundamental research in algebraic geometry"
^{[5]}^{[22]} - 2010 Prize of the Fondation Sciences Mathématiques de Paris
^{[23]} - 2016 AMS Moore Prize
^{[24]} - 2018 Fields Medal.
^{[7]}

## ReferencesEdit

**^**"جایزه معادل "نوبل ریاضی" به یک کرد ایرانی پناهنده به بریتانیا رسید".*VoA*(in Persian). 1 August 2018.**^**"چرا مریم میرزاخانی و کوچر بیرکار مهاجرت کردند؟".*BBC*(in Persian). 3 August 2018.**^**August 4; 2018; Am, 9:15. "Caucher Birkar's family celebrates Fields Medal win | ICM News". Retrieved 2019-03-10.**^**"Birkar Citation" (PDF).*International Mathematical Union*. Birkar long citation. International Mathematical Union. 2018. p. 2.- ^
^{a}^{b}"Archived copy". Archived from the original on 2013-06-10. Retrieved 2012-12-30.CS1 maint: Archived copy as title (link) **^**"American Mathematical Society".*www.ams.org*. Retrieved 1 August 2018.- ^
^{a}^{b}^{c}"Former refugee among winners of Fields medal – the 'Nobel prize for maths'". **^**"Quanta Magazine - Illuminating Science | Quanta Magazine".*Quanta Magazine*. Retrieved 2018-08-07.**^**Draganova, C. "IMC - International Mathematics Competition for University Students".*www.ucl.ac.uk*. Retrieved 2 August 2018.**^**Fields medal: UK refugee wins 'biggest maths prize', by Paul Rincon, at BBC.co.uk; published August 1, 2018; retrieved August 1, 2018**^**"Cecil King Travel Scholarship in Mathematics". Retrieved 3 August 2018.**^**لندن, کیهان (2018-08-02). "مدال "فیلدز" کوچر بیرکار ریاضیدان به سرقت رفت اما افتخارش برای ایرانیان ماندنی است" (in Persian). Retrieved 2018-08-07.**^**C. Birkar, P. Cascini, C. Hacon, J. McKernan Existence of minimal models for varieties of log general type, J. Amer. Math. Soc. 23 (2010), 405–468.**^**Birkar, Caucher (2012). "Existence of log canonical flips and a special LMMP".*Publications Mathématiques de l'IHÉS*.**115**: 325–368. arXiv:1104.4981. doi:10.1007/s10240-012-0039-5.**^**C. Birkar, D.-Q. Zhang, Effectivity of Iitaka fibrations and pluricanonical systems of polarized pairs. To appear in Pub. Math IHES.**^**C. Birkar, Anti-pluricanonical systems on Fano varieties. arXiv:1603.05765**^**C. Birkar, Singularities of linear systems and boundedness of Fano varieties. arXiv:1609.05543.**^**Castelvecchi, Davide (1 August 2018). "Number-theory prodigy among winners of most coveted prize in mathematics".*Nature*.**560**(7717): 152–153. doi:10.1038/d41586-018-05864-w. PMID 30087472.**^**Phillips, Dom (1 August 2018). "World's most prestigious maths medal is stolen alongside his wallet minutes after professor wins it".*The Guardian*.**^**""I'm more famous now than I would be", jokes Birkar",*ICM 2018*, August 4, 2018**^**C. Birkar, Existence of flips and minimal models for 3-folds in char p. Annales scientifiques de l’ENS 49 (2016), 169-212.**^**"Caucher Birkar has been awarded 2010 Philip Leverhulme prize".*wordpress.com*. 22 November 2010. Retrieved 1 August 2018.**^**"Archived copy". Archived from the original on 2014-03-17. Retrieved 2013-06-01.CS1 maint: Archived copy as title (link)**^**"American Mathematical Society".*www.ams.org*. Retrieved 2 August 2018.

## Further readingEdit

- Kevin Hartnett (1 August 2018), "An innovator who brings order to an infinitude of equations",
*Quanta Magazine*.

## External linksEdit

- Some of his papers
- Caucher Birkar at the Mathematics Genealogy Project
- Caucher Birkar publications indexed by the Scopus bibliographic database. (subscription required)