Greg Hjorth
Encyclopedia
Greg Hjorth was an Australian Professor of Mathematics
, chess
International Master (1984) and joint (with Ian Rogers
) Commonwealth Champion
in 1983. He was acknowledged as a world leader in the field of mathematical logic
.
, with a dissertation entitled On the influence of second uniform indiscernible. He held faculty positions at the University of California, Los Angeles
and the University of Melbourne
. Among his most important contributions to set theory
was the so-called theory of turbulence, a powerful technique used in the theory of Borel equivalence relation
s.
in Canberra in 1982, 1985 and 1987 and played for Australia in the Chess Olympiad
s of 1982, 1984 and 1986.
His best single performance was at Brighton (BCF Championship) 1984, where he scored four of seven possible points (57%) against 2551-rated opposition, for a performance rating of 2570.
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
, chess
Chess
Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...
International Master (1984) and joint (with Ian Rogers
Ian Rogers (chess player)
Ian Rogers , is a retired Australian chess grandmaster and FIDE Senior Trainer .-Career:Rogers was the first Australian to become a Chess Grandmaster, a title he achieved in 1985 after becoming an International Master in 1980...
) Commonwealth Champion
Commonwealth Chess Championship
The Commonwealth Chess Championship is a gathering of chess players from Commonwealth countries.-History:A championship was planned for New Zealand in 1949, but it was canceled because the British Chess Federation was unable to attend.-Oxford 1950:...
in 1983. He was acknowledged as a world leader in the field of mathematical logic
Mathematical logic
Mathematical logic is a subfield of mathematics with close connections to foundations of mathematics, theoretical computer science and philosophical logic. The field includes both the mathematical study of logic and the applications of formal logic to other areas of mathematics...
.
Mathematical career
Hjorth earned his Ph.D. in 1993, under the direction of W. Hugh WoodinW. Hugh Woodin
William Hugh Woodin is an American mathematician and set theorist at University of California, Berkeley. He has made many notable contributions to the theory of inner models and determinacy. A type of large cardinal, the Woodin cardinal, bears his name.-Biography:Born in Tucson, Arizona, Woodin...
, with a dissertation entitled On the influence of second uniform indiscernible. He held faculty positions at the University of California, Los Angeles
University of California, Los Angeles
The University of California, Los Angeles is a public research university located in the Westwood neighborhood of Los Angeles, California, USA. It was founded in 1919 as the "Southern Branch" of the University of California and is the second oldest of the ten campuses...
and the University of Melbourne
University of Melbourne
The University of Melbourne is a public university located in Melbourne, Victoria. Founded in 1853, it is the second oldest university in Australia and the oldest in Victoria...
. Among his most important contributions to set theory
Set theory
Set theory is the branch of mathematics that studies sets, which are collections of objects. Although any type of object can be collected into a set, set theory is applied most often to objects that are relevant to mathematics...
was the so-called theory of turbulence, a powerful technique used in the theory of Borel equivalence relation
Borel equivalence relation
In mathematics, a Borel equivalence relation on a Polish space X is an equivalence relation on X that is a Borel subset of X × X....
s.
Chess career
Hjorth won the Doeberl CupDoeberl Cup
The Doeberl Cup is an annual chess tournament held in Canberra, Australia. It has been held every year since 1963 and is the longest running weekend chess event in Australia. Since its inception the event has grown both larger and stronger, and often attracts more players than the Australian Chess...
in Canberra in 1982, 1985 and 1987 and played for Australia in the Chess Olympiad
Chess Olympiad
The Chess Olympiad is a biennial chess tournament in which teams from all over the world compete against each other. The event is organised by FIDE, which selects the host nation.-Birth of the Olympiad:The first Olympiad was unofficial...
s of 1982, 1984 and 1986.
His best single performance was at Brighton (BCF Championship) 1984, where he scored four of seven possible points (57%) against 2551-rated opposition, for a performance rating of 2570.
Book
- G. Hjorth: Classification and Orbit Equivalence Relations, Mathematical Surveys and Monographs, 75, American Mathematical SocietyAmerican Mathematical SocietyThe American Mathematical Society is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, which it does with various publications and conferences as well as annual monetary awards and prizes to mathematicians.The society is one of the...
, Providence, Rhode Island, 2000.