Jesse Ratzkin
Dr. Jesse Ratzkin
 Foliation of an asymptotically flat end by critical capacitors. (joint with M. M. Fall and I. A. Minlend) preprint, arxiv:2007.05323
 On an fourth order conformal invariant. preprint, arxiv:2002.05939
 On constant Qcurvature metrics with isolated singularities. preprint, arxiv:2001.07984
 On the rate of change of the best constant in the Sobolev inequality. (joint with T. Carroll and M. M. Fall), Math. Nachr. 290 (2017), 2185–2197.
 Monotonicity of the first Dirichlet eigenvalue of the Laplacian on manifolds with nonpositive curvature. (joint with T. Carroll), Indiana Univ. Math. J. 65 (2016), 353–376.
 A reverse Hölder inequality for extremal Sobolev functions. (joint with T. Carroll), Potential Anal. 42 (2015), 283–292.
 A numerical investigation of level sets of extremal Sobolev functions. (joint with S. Juhnke), Involve 8 (2015), 787–799. (This paper is essentially S. Juhnke’s 2013 honors dissertation.)
 An isoperimetric inequality for extremal Sobolev functions. (joint with T. Carroll), RIMS Kôkyûroku Bessatsu, B43 (2013), 1–16.
 Two isoperimetric inequalities for the Sobolev constant. (joint with T. Carroll), Z. Angew. Math. Phys., 63 (2012), 855–863.
 Isoperimetric inequalities and variations on Schwarz’s lemma (joint with T. Carroll), arXiv:SP/1006.2310 (This paper has been subsumed by the above paper in Z. Angew. Math. Phys.)
 Interpolating between torsional rigidity and principal frequency (joint with T. Carroll), J. Math. Anal. Appl., 379 (2011), 818–826.
 Eigenvalues of Euclidean wedge domains in higher dimensions, Calc. Var. PDE, 42 (2011), 93–106.
 A PayneWeinberger estimate for wedge domains on spheres (joint with A. Treibergs), Proc. Amer. Math. Soc. 137 (2009), 2299–2309.
 Coplanar kunduloids are nondegenerate (joint with K. GrosseBrauckmann, N. Korevaar, R. Kusner, and J. Sullivan), Int. Math. Res. Not., 2009 (2009), 3391–3416.
 A capture problem in Brownian motion and eigenvalues of spherical domains (joint with A. Treibergs), Trans. Amer. Math. Soc. 361 (2009), 391–405.
 On the nondegeneracy of constant mean curvature surfaces (joint with N. Korevaar and R. Kusner), Geom. Funct. Anal. 16 (2006), 891–923.
 An end to end gluing construction for metrics of constant positive scalar curvature, Indiana Univ. J. Math. 52 (2003), 703–726.
Employment
 Wissenschaftlicher Mitarbeiter, Institut für Mathematic, Universität Würzburg, Nov 2017present
 Permanent Lecturer, University of Cape Town, August 2010–June 2016 (this is equivalent to a tenured assistant professor position in the US)
 Visiting Lecturer, University College Cork, Sept. 2009–June 2010
 Postdoctoral Fellow (under B. McKay), University College Cork, Sept. 2008–Sept. 2009
 Temporary Assistant Professor, University of Georgia, August 2007–May 2008
 Postdoctoral Fellow, University of Connecticut, August 2004–May 2007
 Postdoctoral Fellow, University of Utah: August 2001–May 2004
Research Interests
 geometric analysis
 specifically mean curvature
 scalar curvature, Qcurvature,
 eigenvalues of the LaplaceBeltrami operator,
 isoperimetric inequalities in the spirit of Pólya and Szegő
Education
 August 2001:Ph.D. in mathematics, University of Washington, , Thesis: An End to End Gluing Construction for Surfaces of Constant Mean Curvature, Advisor: Daniel Pollack
 May 1995: B.A. in mathematics, University of California at Berkeley
Honors, Awards, and Funding
 rated researcher by the National Research Foundation of South Africa, Jan. 1, 2013 June 30, 2016(This entitled me to R40, 000 per year towards research.)
 Carnegie Research Development Grant, funded by the University of Cape Town
 Postdoctoral Fellow Sept. 2008June 2009, funded by the Science Foundation of Ireland
 VIGRE fellow, January–June 2001, funded by the National Science Foundation of the US
Invited Lectures
 Online Geometric Analysis Seminar, May 2020 (https://blatt.sbg.ac.at/onlineseminar.php)
 Analysis seminar, University College Dublin, Dublin, Ireland, Feb. 2016
 Special session on geometries defined by differential forms at the Joint National Meeting of the American Mathematical Society and Mathematical Association of America, San Antonio, USA, Jan. 2015
 Special session on geometric variational problems at the Tenth American Institute of Mathematical Sciences conference on Dynamical Systems, Differential Equations, and Applications, Madrid, Spain, July 2014
 Workshop on Kähler geometry and geometric analysis, Cork, Ireland, May 2014
 Geometry/Topology/Analysis seminar, University of Massachusetts, Amherst, MA, USA, April 2014
 Differential geometry seminar, City University of New York, New York, NY, USA, April 2014
 Geometry seminar, University of Rochester, Rochester, NY, USA, April 2014
 Analysis seminar, University College Dublin, Dublin, Ireland, March 2014
 Colloquium, School of Mathematical Sciences, University College Cork, Cork, Ireland, Feb. 2014
 Special session on complex and geometric analysis at the Joint National Meeting of the American Mathematical Society and Mathematical Association of America, Baltimore, USA, Jan. 2014
 Special session on analysis and PDE at the Joint National Meeting of the American Mathematical Society and the Mathematical Association of America, Baltimore, USA, Jan 2014
 Special session on geometry at the national congress of the South African Mathematical Society, Pietermaritzburg, South Africa, Nov. 2013
 Special session on geometry and differential equations at the national congress of the South African Mathematical Society, Port Elizabeth, South Africa, Dec. 2011
 Geometric Analysis Seminar, University of Helsinki, Helsinki, Finland, Sept. 2011
 Workshop on de Giorgi’s conjecture, Banff International Research Station, Banff, Canada, Aug. 2010
 Workshop on Geometry, Analysis, and String Theory, Leibniz University, Hannover, Germany, July 2009
 Irish Geometry Conference, University College Cork, Cork, Ireland May 2009• Geometry Day, Granada, Spain, Dec. 2008
 Geometry Seminar, Stanford University, Palo Alto, USA, May 2008
 18th Southeast Geometry Conference, Columbia, SC, USA, March 2008
 Geometry Seminar, Georgia Institute of Technology, Atlanta, USA, Dec. 2007
 Progress in Surface Theory, workshop at Oberwolfach, Germany, May 2007
 Differential Geometry seminar, City University of New York, New York, USA, Oct.2006
 Differential Geometry Seminar, Massachusetts Institute of Technology, Cambridge, USA, April 2006
 Valley Geometry Seminar, UMass, Amherst, USA, Feb. 2006
 Differential Geometry/PDE seminar, Univ. Washington, Seattle, USA, May 2005
 16th Southeast Geometry Conference, Columbia, SC, USA, March 2005
 Geometry seminar, University of Massachusetts, Amherst, USA, April 2001, Feb. 2002,
 October/November 2004, April 2005
 Geometry seminar, Idaho State University, Pocatello, USA, June 2004
 Special session on nonlinear partial differential equations at the Joint National Meeting of the American Mathematical Society and Mathematical Association of America, Phoenix, AZ, USA, Jan. 2004
 Topology seminar, Georgia Institute of Technology,Atlanta, USA, Dec. 2002
 Special session in the Winter Meeting of the Canadian Mathematical Society, Toronto, Canada, Dec. 2001
Contributed Talks
 Conference on Teaching and Learning, University of Cape Town, Oct. 2013
 Conference in Geometric Analysis, Universidad Autònoma de Barcelona, July 2013.
 Queen Dido Conference on Isoperimetry, Carthage, Tunisia, May 2010
 Summer School in Conformal Geometry, Potential Theory, and Applications, NUI Maynooth, Ireland, June 2009
 Lehigh University Geometry and Topology Conference, Oct. 2007
Academic and Professional Service
 member of the editorial board, Quaestiones Mathematicae
 member of the planning committee, Department of Mathematics and Applied Mathematics, University of Cape Town, July 2014–Dec. 2015
 member of the executive committee of the African Mathematical Sciences Institute, Muizenberg, South Africa, Feb. 2012–Dec. 2015
 external examiner for third year complex analysis, University of the North West, South Africa, 20142015
 external examiner of the MSc dissertation of C. A. Emereuwa, University of Pretoria, South Africa, 2015
 chair of a committee to reorganize the second and third year courses in pure and applied mathematics at the University of Cape Town
 member of a search committee to find a new head of the mathematics department at the University of Cape Town
 introduction and pioneer use of WebWork, an online homework tool, for first and second year mathematics courses at the University of Cape Town
 overhaul of the departmental webpage for the Department of Mathematics and Applied Mathematics, University of Cape Town (with Rob Martin and Julian Gordon [the departmental IT officer])
 referee for Inventiones Mathematicae, Experimental Mathematics, Annales de la Faculté des Sciences de Toulouse, Colloquium Mathematicum, Bulletin of the London Mathematical Society, Publicaciones Matemàtiques
 reviewer for Math Reviews
 organizer for a workshop in geometric analysis at the African Institute of Mathematical Sciences, Dec. 2012
 organizer for a special session in geometric differential equations at the 2011 South African Mathematical Society national congress in Port Elizabeth
 coorganizer for a special session in the fall 2006 American Mathematical Society northeastern sectional meeting
 coorganizer of research level Geometry seminar at U. Connecticut, September 2004–May 2007
 organizer for the spring 2004 meeting of the Pacific Northwest Geometry Seminar
 coorganizer of research level PDE/Differential Geometry seminar at U. Utah, August 2003–May 2004
 assisted with a VIGRE Minicourse in nonlinear wave phenomena, August 2003
 faculty advisor for the graduate student geometry seminar, August–December, 2002
 assisted with a VIGRE Minicourse in variation methods and nonlinear PDE, particularly
 in organizing a series of lectures on minimal surfaces, May 2002
 organizer of graduate student geometry seminar, 1998–2000
Outreach and Community Service
 guest lecturer in mathematical enrichment sessions for secondary school students in Cape Town, South Africa, March 2012 and August 2011 (three lectures, one each on the isoperimetric inequality, knots, and coloring of graphs)
 led mathematical enrichment sessions for secondary school students in Cork, Ireland, Febuary 2010 (two sessions, one each on inequalities and a discrete model for heat flow)
 led a series of three lectures on fractals in the University of Utah Math Circle, a high school outreach program, April 2003
 assisted with the Math Circle program, September 2002–May 2004
Current courses

Mathematics for Computer Scientists 1: 5 hrs, Mon 1012, Wed 1114, J. Ratzkin

Exercises in Mathematics for Computer Scientists 1 in groups: 2 pc, Mon 1214 ; Mon 1416 ; Mon 1618 ; Tue,Wed 810, J. Ratzkin
Teaching Experience
 At Universität Würzburg I have staffed exercise sessions in analysis II and III, function theory (complex analysis), first year mathematics for physicists, and differential geometry of curves and surfaces.
 I was a part of the lecturing team for the standard first year mathematics course at the University of Cape Town, JulyNov. 2012 and JulyNov. 2014.
 I have also assisted in teaching classes ranging from freshman calculus to graduate geometry and topology, led discussion sections, staffed dropin tutoring centers, and graded for a variety of courses.
I have been the sole instructor or course leader (which includes writing syllabi, course notes, and exams) for the following courses.
 at the University of Cape Town:
– first year course for applied mathematics (MAM1044, 2011)
– fourth year (honors) course in PDE (2011, 2012, 2013, and 2015)
– second year linear algebra (MAM20002LA, 2012, 2013, and 2015)
– second year differential equations (MAM20002DE, 2013, 2014, and 2015)
 at University College Cork:
– real analysis II (MA3051, undergraduate, fall 2009)
– introductory mathematics (MA1003, fall 2009 and spring 2010)
– topology and metric spaces (MA3056, spring 2010)
 at the University of Georgia:
– abstract algebra (undergraduate, fall 2007)
– singlevariable calculus (fall 2007)
– multivariable calculus (spring 2008)
– Euclidean geometry (spring 2008)
 at the University of Connecticut:
– singlevariable calculus (fall 2004, fall 2006)
– geometry (fall 2004, spring 2005),
– multivariable calculus (spring 2005, fall 2005, fall 2006)
– ordinary differential equations (spring 2006, spring 2007)
– complex analysis (spring 2006)
– writing in mathematics (spring 2007)
 at the University of Utah:
– partial differential equations for engineers (fall 2003)
– topics in Riemannian geometry: the Yamabe problem (spring 2003)
– trigonometry (fall 2002)
– linear algebra (spring 2002)
– ordinary differential equations (fall 2001, spring 2004)
 at the University of Washington:
– multivariable calculus (summer 2000, spring 1999)
– ordinary differential equations (summer 1999)
– first year calculus (summer 1997)
– remedial algebra (winter 1997)
Student Supervision
 Murray Christian, PhD at the University of Cape Town, May 2011Feb. 2019 Dissertation, title: Constant mean curvature 12 surfaces in H 2 × R.
 Mogtaba Mohammed, AIMS postgraduate diploma, Feb.–June 2011. Topic: Weyl’s asymptotic formula for eigenvalues of the Laplacian.
 Humphrey Marufu, honours project at the University of Cape Town, MarchNov. 2012. Topic: extremal domains for three variational problems.
 Stefan Juhnke, honours project at the University of Cape Town, Feb–Nov. 2013. Topic: geometry of level sets of extremal Sobolev functions.
 8 final year capstone projects in topics including the maximum principle for elliptic PDE, the classical isoperimetric inequality, maximal surfaces in Minkowski space, classification of hyperbolic isometries, and groups & threedimensional manifolds.