Theta Surfaces
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Theta Surfaces Bernd Sturmfels MPI Leipzig and UC Berkeley Joint Work with Daniele Agostini, T¨urk¨u Ozl¨um¨ C¸elik and Julia Struwe A second parametrization: u+v X = arctan(u)+arctan(v)=arctan 1 uv − 5u+5v Y = arctan(5u)+arctan(5v)=arctan 1 25uv − 1 1+(5u)2 1 1+(5v)2 Z = 2 log 5(1+u2) + 2 log 5(1+v 2) This theta surface is derived from the following quartic curve in the complex projective plane P2: xy(x2 + y 2 + z2)=0. Scherk’s Minimal Surface Our running example is the surface in R3 given by sin(X ) sin(Y ) exp(Z)=0. − · This theta surface has the parametric representation (X , Y , Z)= arctan(s), 0 , log(s) log(s2+1)/2 − + 0 , arctan(t) , log(t)+log(t2+1)/2 . − Scherk’s Minimal Surface Our running example is the surface in R3 given by sin(X ) sin(Y ) exp(Z)=0. − · This theta surface has the parametric representation (X , Y , Z)= arctan(s), 0 , log(s) log(s2+1)/2 − + 0 , arctan(t) , log(t)+log(t2+1)/2 . − A second parametrization: u+v X = arctan(u)+arctan(v)=arctan 1 uv − 5u+5v Y = arctan(5u)+arctan(5v)=arctan 1 25uv − 1 1+(5u)2 1 1+(5v)2 Z = 2 log 5(1+u2) + 2 log 5(1+v 2) This theta surface is derived from the following quartic curve in the complex projective plane P2: xy(x2 + y 2 + z2)=0. Scherk’s Minimal Surface sin(X )=sin(Y ) exp(Z) · (X , Y , Z)= arctan(s), 0 , log(s) log(s2+1)/2 − + 0 , arctan(t) , log(t)+log(t2+1)/2 . − Double Translation Surfaces An analytic surface in R3 or C3 is a double translation surface S if it has two distinct representations as Minkowski sum of curves: Bilder Druckqualität - Files - ownCloud 11.02.20, 10'00 Bilder Druckqualität - Files - ownCloud 11.02.20, 09(58 Add to your ownCloud Download Add to your ownCloud= Download1 + 2 = 3 + 4 S C Objekt C05 Bilder DruckqualitätC C Objekt 03-04 Bilder Druckqualität Name Size Modified Name Size Modified Bild_01 3.2 MB 6 days ago Bild_01 4.6 MB 6 days ago Bild_02 3.4 MB 6 days ago Bild_02 3.6 MB 6 days ago Bild_03 3.6 MB 6 days ago Bild_03 3.6 MB 6 days ago Bild_04 3.1 MB 6 days ago Bild_04 3.6 MB 6 days ago Bild_05 3.4 MB 6 days ago 4 files 13.3 MB Bild_06 3.6 MB 6 days ago Bild_07 2.3 MB 6 days ago Bild_08 2.7 MB 6 days ago 8 files 27.3 MB Imprint | Privacy Policy Sophus Lie: Bestimmung aller Fl¨achendie in mehrfacher Weise durch Translationsbewegung einer Curve erzeugt werden, Archiv Math. (1882). Imprint | Privacy Policy https://oc.mis.mpg.de/s/lkLFiv2kfnD6rWS?path=%2FObjekt%2003-04%2…ruckqualität#/Objekt%2003-04/Bilder%20Druckqualität/Bild_02.jpg Page 1 of 1 https://oc.mis.mpg.de/s/lkLFiv2kfnD6rWS?path=%2FObjekt%2005%2FBi…20Druckqualität#/Objekt%2005/Bilder%20Druckqualität/Bild_02.jpg Page 1 of 1 In 1892 Lie published an article explaining how these surfaces can be parametrized by abelian integrals. In 1895 Henri Poincar´e gave his proof of the relationship to Abel’s Theorem. This led to the idea that these surfaces are theta divisors of 3-dim’l Jacobians. Lie supervised two doctoral dissertations on this topic at Leipzig. His students constructed a series of plaster models that visualize the diverse shapes exhibited by theta surfaces. It is surprising that the models were commissioned by Lie, who, unlike Klein, had not been known so far for an engagement in popularizing geometry. Leipzig Felix Klein held the professorship for geometry at Leipzig until 1886 when he moved to G¨ottingen. Sophus Lie was appointed to be Klein’s successor and he moved from Christiania (Oslo) to Leipzig. In his first years, Lie was busy with completing his major work Theory of Transformation Groups.Thereafter,double translation surfaces moved back in the focus of his teaching and research. Lie supervised two doctoral dissertations on this topic at Leipzig. His students constructed a series of plaster models that visualize the diverse shapes exhibited by theta surfaces. It is surprising that the models were commissioned by Lie, who, unlike Klein, had not been known so far for an engagement in popularizing geometry. Leipzig Felix Klein held the professorship for geometry at Leipzig until 1886 when he moved to G¨ottingen. Sophus Lie was appointed to be Klein’s successor and he moved from Christiania (Oslo) to Leipzig. In his first years, Lie was busy with completing his major work Theory of Transformation Groups.Thereafter,double translation surfaces moved back in the focus of his teaching and research. In 1892 Lie published an article explaining how these surfaces can be parametrized by abelian integrals. In 1895 Henri Poincar´e gave his proof of the relationship to Abel’s Theorem. This led to the idea that these surfaces are theta divisors of 3-dim’l Jacobians. Leipzig Felix Klein held the professorship for geometry at Leipzig until 1886 when he moved to G¨ottingen. Sophus Lie was appointed to be Klein’s successor and he moved from Christiania (Oslo) to Leipzig. In his first years, Lie was busy with completing his major work Theory of Transformation Groups.Thereafter,double translation surfaces moved back in the focus of his teaching and research. In 1892 Lie published an article explaining how these surfaces can be parametrized by abelian integrals. In 1895 Henri Poincar´e gave his proof of the relationship to Abel’s Theorem. This led to the idea that these surfaces are theta divisors of 3-dim’l Jacobians. Lie supervised two doctoral dissertations on this topic at Leipzig. His students constructed a series of plaster models that visualize the diverse shapes exhibited by theta surfaces. It is surprising that the models were commissioned by Lie, who, unlike Klein, had not been known so far for an engagement in popularizing geometry. Bilder Druckqualität - Files - ownCloud 11.02.20, 09(59 Bilder Druckqualität - Files - ownCloud 11.02.20, 09(59 Students of Sophus Lie Add to your ownCloud Download Add to your ownCloud Download Objekt 02 Bilder Druckqualität Objekt 01 Bilder Druckqualität Name Size Modified Name Size Modified Bild_01 1.5 MB 7 days ago Bild_01 4.7 MB 7 days ago Bild_02 2.2 MB 7 days ago Bild_02 4 MB 7 days ago Bild_03 2.2 MB 7 days ago Bild_03 3.2 MB 7 days ago Bild_04 1.9 MB 7 days ago Bild_04 3.1 MB 7 days ago Bild_05 2.3 MB 7 days ago Bild_05 2.8 MB 7 days ago Bild_06 3.1 MB 7 days ago Bild_06 2.4 MB 7 days ago 6 files 13.2 MB 6 files 20.3 MB Richard Kummer: Die Fl¨achen mit unendlichvielen Erzeugungen durchImprint | Privacy Translation Policy von Kurven, Dissertation,Imprint Universit¨at | Privacy Policy Leipzig, 1894. https://oc.mis.mpg.de/s/lkLFiv2kfnD6rWS?path=%2FObjekt%2001%2FBi…%20Druckqualität#/Objekt%2001/Bilder%20Druckqualität/Bild_03.jpghttps://oc.mis.mpg.de/s/lkLFiv2kfnD6rWS?path=%2FObjekt%2002%2FBi…20Druckqualität#/Objekt%2002/Bilder%20Druckqualität/Bild_02.jpgPage 1 of 1 Page 1 of 1 Bilder Druckversion - Files - ownCloud 11.02.20, 10'01 Add to your ownCloud Download StudentsObjekt 07-08-09 of SophusBilder Druckversion Lie Name Size Modified Bild_01 4.5 MB 6 days ago Bild_02 5.2 MB 6 days ago Bild_03 3.2 MB 6 days ago Bild_04 4.6 MB 6 days ago Bild_05 2.6 MB 6 days ago Bild_06 2.5 MB 6 days ago 6 files 22.6 MB Georg Wiegner: Uber¨ eine besondere Klasse von Translationsfl¨achen, Dissertation, Universit¨at Leipzig, 1893. Imprint | Privacy Policy https://oc.mis.mpg.de/s/lkLFiv2kfnD6rWS?path=%2FObjekt%2007-08-…uckversion#/Objekt%2007-08-09/Bilder%20Druckversion/Bild_02.jpg Page 1 of 1 John Arndt Eiesland - Wikipedia 11.02.20, 10'53 John Arndt Eiesland Johan "John" Arndt Eiesland (27 January 1867, Ny-Hellesund, Norway – 11 March 1950, West Virginia Morgantown, West Virginia) was a Norwegian-American mathematician, specializing in differential geometry. Eiesland immigrated to the USA in 1888 after completing his secondary education in Christiansand. He received his bachelor's degree from the University of South Dakota in 1891. He was a mathematics professor from 1895 to 1903 at Thiel College in Pennsylvania. On a leave of absence, he studied mathematics as a Johns Hopkins Scholar (1897–1898) at Johns Hopkins University, where he received his Ph.D. in 1898.[1] From 1903 to 1907 he was a mathematics instructor at the United States Naval Academy. In 1907 he became a professor of mathematics at West Virginia University and the chair of the mathematics department from 1907 to 1938, when he retired as professor emeritus.[2] Eiesland was elected a Fellow of the American Association for the Advancement of Sciences in 1903.[3] He was an Invited Speaker of the ICM in 1924 in Toronto. He married in 1904. At West Virginia University, Eiesland Hall is named in his honor, and in 1994 his heirs established the John Arndt Eiesland Visiting Professorship of Mathematics.[4] Selected publications On Nullsystems in space of five dimensions and their relation to ordinary space. (https://bab el.hathitrust.org/cgi/pt?id=njp.32101043987906;view=1up;seq=119) American Journal of Mathematics 26, no. 2 (1904): 103-148. On a certain system of conjugate lines on a surface connected with Euler's transformation. Trans. Amer.