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Ott-Heinrich Keller (cropped)
Eduard Ott-Heinrich Keller (22 June 1906 in Frankfurt – 5 December 1990 in Halle (Saale), Halle) was a German mathematician who worked in the fields of geometry, topology and algebraic geometry. He formulated the celebrated problem which is now called the Jacobian conjecture in 1939. He was born in Frankfurt–am-Main, and studied at the universities of Frankfurt, Vienna, Berlin and Göttingen. As a student of Max Dehn he wrote a dissertation on the tessellation, tiling of space with cubes. This led to another 'Keller conjecture': the Keller cube-tiling conjecture from 1930. Subsequently he worked with Georg Hamel in Berlin, habilitation, habilitating in 1933 with a thesis on Cremona transformations. The Jacobian conjecture is quite naturally posed in that setting. The motivation for looking at rather general polynomial transformations, say of the projective plane, came from the singularity theory for algebraic curves. During World War II he taught in a naval college in Flens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ott-Heinrich Keller (cropped)
Eduard Ott-Heinrich Keller (22 June 1906 in Frankfurt – 5 December 1990 in Halle (Saale), Halle) was a German mathematician who worked in the fields of geometry, topology and algebraic geometry. He formulated the celebrated problem which is now called the Jacobian conjecture in 1939. He was born in Frankfurt–am-Main, and studied at the universities of Frankfurt, Vienna, Berlin and Göttingen. As a student of Max Dehn he wrote a dissertation on the tessellation, tiling of space with cubes. This led to another 'Keller conjecture': the Keller cube-tiling conjecture from 1930. Subsequently he worked with Georg Hamel in Berlin, habilitation, habilitating in 1933 with a thesis on Cremona transformations. The Jacobian conjecture is quite naturally posed in that setting. The motivation for looking at rather general polynomial transformations, say of the projective plane, came from the singularity theory for algebraic curves. During World War II he taught in a naval college in Flens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habilitation
Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including a dissertation. The degree, abbreviated "Dr. habil." (Doctor habilitatus) or "PD" (for "Privatdozent"), is a qualification for professorship in those countries. The conferral is usually accompanied by a lecture to a colloquium as well as a public inaugural lecture. History and etymology The term ''habilitation'' is derived from the Medieval Latin , meaning "to make suitable, to fit", from Classical Latin "fit, proper, skillful". The degree developed in Germany in the seventeenth century (). Initially, habilitation was synonymous with "doctoral qualification". The term became synonymous with "post-doctoral qualification" in Germany in the 19th century "when holding a doctorate seemed no longer sufficient to guarantee a proficient transfer o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1990 Deaths
Year 199 ( CXCIX) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was sometimes known as year 952 '' Ab urbe condita''. The denomination 199 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Mesopotamia is partitioned into two Roman provinces divided by the Euphrates, Mesopotamia and Osroene. * Emperor Septimius Severus lays siege to the city-state Hatra in Central-Mesopotamia, but fails to capture the city despite breaching the walls. * Two new legions, I Parthica and III Parthica, are formed as a permanent garrison. China * Battle of Yijing: Chinese warlord Yuan Shao defeats Gongsun Zan. Korea * Geodeung succeeds Suro of Geumgwan Gaya, as king of the Korean kingdom of Gaya (traditional date). By topic Religion * Pope Zephyrinus succeeds Pope Victor I, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1906 Births
Events January–February * January 12 – Persian Constitutional Revolution: A nationalistic coalition of merchants, religious leaders and intellectuals in Persia forces the shah Mozaffar ad-Din Shah Qajar to grant a constitution, and establish a national assembly, the Majlis. * January 16–April 7 – The Algeciras Conference convenes, to resolve the First Moroccan Crisis between France and Germany. * January 22 – The strikes a reef off Vancouver Island, Canada, killing over 100 (officially 136) in the ensuing disaster. * January 31 – The Ecuador–Colombia earthquake (8.8 on the Moment magnitude scale), and associated tsunami, cause at least 500 deaths. * February 7 – is launched, sparking a naval race between Britain and Germany. * February 11 ** Pope Pius X publishes the encyclical ''Vehementer Nos'', denouncing the 1905 French law on the Separation of the Churches and the State. ** Two British members of a poll tax collecting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich Jung
Heinrich Wilhelm Ewald Jung (4 May 1876, Essen – 12 March 1953, Halle (Saale)) was a German mathematician, who specialized in geometry and algebraic geometry. Biography Heinrich Jung was born as the son of a ''Bergrat'' (a mining officer of high rank) in Essen and studied from 1895 to 1899 mathematics, physics, and chemistry in Marburg/Lahn and Berlin under outstanding professors including Friedrich Schottky, Kurt Hensel, Lazarus Immanuel Fuchs, Hermann Amandus Schwarz, Ferdinand Georg Frobenius, and Max Planck. In his 1899 doctoral dissertation ''Über die kleinste Kugel, die eine räumliche Figur einschließt'' under Schottky he proved the eponymous Jung's Theorem. In 1902 he completed his Habilitation thesis in Marburg and remained there until 1908 as a privatdocent. Afterwards he was a Studienrat (teacher at a secondary school, ''i.e.'', ''Gymnasium'') in Hamburg, before he became in 1913 a professor ordinarius in Kiel. After brief military service in World War I he beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Luther University Of Halle-Wittenberg
Martin Luther University of Halle-Wittenberg (german: Martin-Luther-Universität Halle-Wittenberg), also referred to as MLU, is a public, research-oriented university in the cities of Halle and Wittenberg and the largest and oldest university in the German state of Saxony-Anhalt. MLU offers German and international (English) courses leading to academic degrees such as BA, BSc, MA, MSc, doctoral degrees, and Habilitation. The university was created in 1817 through the merger of the University of Wittenberg (founded in 1502) and the University of Halle (founded in 1694). MLU is named after Protestant reformer Martin Luther, who was a professor in Wittenberg. Today, the university campus is located in Halle, while ''Leucorea Foundation'' in Wittenberg serves as MLU's convention centre. Both Halle and Wittenberg are about one hour from Berlin via the Berlin–Halle railway, which offers Intercity-Express (ICE) trains. History University of Wittenberg (''Universität Wittenbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flensburg
Flensburg (; Danish, Low Saxon: ''Flensborg''; North Frisian: ''Flansborj''; South Jutlandic: ''Flensborre'') is an independent town (''kreisfreie Stadt'') in the north of the German state of Schleswig-Holstein. Flensburg is the centre of the region of Southern Schleswig. After Kiel and Lübeck, it is the third largest town in Schleswig-Holstein. The nearest larger towns are Kiel ( south) and Odense in Denmark ( northeast). Flensburg's city centre lies about from the Danish border. Known for In Germany, Flensburg is known for: * the Kraftfahrt-Bundesamt (roughly: National Driver and Vehicle Register) with its ''Verkehrssünderkartei'' (literally: "traffic sinner card file"), where details of traffic offences are stored * its beer '' Flensburger Pilsener'', also called "''Flens''" * the centre of the Danish national minority in Germany * the greeting Moin Moin * the large erotic mail-order companies ''Beate Uhse'' and ''Orion'' * its handball team SG Flensburg-Handewitt * th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algebraic Curve
In mathematics, an affine algebraic plane curve is the zero set of a polynomial in two variables. A projective algebraic plane curve is the zero set in a projective plane of a homogeneous polynomial in three variables. An affine algebraic plane curve can be completed in a projective algebraic plane curve by homogenizing its defining polynomial. Conversely, a projective algebraic plane curve of homogeneous equation can be restricted to the affine algebraic plane curve of equation . These two operations are each inverse to the other; therefore, the phrase algebraic plane curve is often used without specifying explicitly whether it is the affine or the projective case that is considered. More generally, an algebraic curve is an algebraic variety of dimension one. Equivalently, an algebraic curve is an algebraic variety that is birationally equivalent to an algebraic plane curve. If the curve is contained in an affine space or a projective space, one can take a projection for such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Singularity Theory
In mathematics, singularity theory studies spaces that are almost manifolds, but not quite. A string can serve as an example of a one-dimensional manifold, if one neglects its thickness. A singularity can be made by balling it up, dropping it on the floor, and flattening it. In some places the flat string will cross itself in an approximate "X" shape. The points on the floor where it does this are one kind of singularity, the double point: one bit of the floor corresponds to more than one bit of string. Perhaps the string will also touch itself without crossing, like an underlined "U". This is another kind of singularity. Unlike the double point, it is not ''stable'', in the sense that a small push will lift the bottom of the "U" away from the "underline". Vladimir Arnold defines the main goal of singularity theory as describing how objects depend on parameters, particularly in cases where the properties undergo sudden change under a small variation of the parameters. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projective Plane
In mathematics, a projective plane is a geometric structure that extends the concept of a plane. In the ordinary Euclidean plane, two lines typically intersect in a single point, but there are some pairs of lines (namely, parallel lines) that do not intersect. A projective plane can be thought of as an ordinary plane equipped with additional "points at infinity" where parallel lines intersect. Thus ''any'' two distinct lines in a projective plane intersect at exactly one point. Renaissance artists, in developing the techniques of drawing in perspective, laid the groundwork for this mathematical topic. The archetypical example is the real projective plane, also known as the extended Euclidean plane. This example, in slightly different guises, is important in algebraic geometry, topology and projective geometry where it may be denoted variously by , RP2, or P2(R), among other notations. There are many other projective planes, both infinite, such as the complex projective plane, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
