University of Maryland

College Park, MD 20742

karin at math.umd.edu

(301) 405-5148

I am an Associate Professor at the University of Maryland in College
Park, partially supported by the National Science Foundation.
Here is a link to the University of Maryland Geometry-Topology seminar. |

- differential-geometric aspects of rigidity
- Lorentz geometry
- conformal pseudo-Riemannian geometry
Papers:

*Quasihomogeneous three-dimensional real analytic Lorentz metrics do not exist**in pdf, with Sorin Dumitrescu*

posted at http://arxiv.org/abs/1406.2302

*Essential Killing fields of parabolic geometries: projective and conformal structures*, with Andreas Čap

*pdf**or in the*ESI Preprint Series (number 2393)

*Central European Journal of Mathematics***11**no. 12 (2013) 2053-2061*Essential Killing fields of parabolic geometries*in*pdf,*with Andreas Čap

posted at http://arxiv.org/abs/1208.5510

and in the ESI Preprint Series (number 2388)

*Indiana University Mathematics Journal***62**no. 6 (2013) 1917-1953*Formes normales pour les champs conformes pseudo-riemanniens [Normal forms for pseudo-Riemannian conformal vector fields]*, with Charles Frances

*dvi**pdf**ps*

*Bulletin de la Société Mathématique de France***141**no. 3 (2013), 377-421*A Frobenius theorem for Cartan geometries, with applications*

*dvi**pdf**ps*

*L'Enseignement Mathématique (Sér. II)***57**no. 1-2 (2011) 57-89

**Caution**: There is an error, indicated to me by Vincent Pecastaing, in the proof of Theorem 6.3, the Frobenius theorem for Killing fields around regular points in the smooth case. I am working on fixing this proof; meanwhile, Pecastaing has an alternative proof of this result for Killing fields in the smooth case, which can be found at arxiv.org/abs/1402.5048. There are no known issues with the real-analtyic results that constitute the bulk of my paper.*Conformal actions of nilpotent groups on pseudo-Riemannian manifolds*, with Charles Frances

*dvi**pdf**ps*

*Duke Mathematical Journal***153**no. 3 (2010) 511-550*Dynamics on Lorentz manifolds*, lecture notes in English from the École de Géométrie Différentielle et Systèmes Dynamiques, ENSET Oran, Algeria, November 4-9, 2006

*dvi**pdf**ps*

French version, translated by D. Smai, in*Algèbre, analyse, et dynamique pour la géométrie: Actes des Écoles de Géométrie et Dynamique au Maghreb 2004-2007*(eds. T. Barbot, H. Belbachir, S. Mehdi, D. Smai, R. Souam) Paris: Ellipses (2010) 307-342*An embedding theorem for automorphism groups of Cartan geometries*, with Uri Bader and Charles Frances

*dvi**pdf**ps*

*Geometric and Functional Analysis***19**no. 2 (2009) 333-355*Compact Lorentz manifolds with local symmetry*

University of Chicago dissertation, 2006*dvi**pdf**ps*

article version*dvi**pdf**ps*

*Journal of Differential Geometry***81**no. 2 (2009) 355-390*A primer on the (2+1) Einstein universe*, with Thierry Barbot, Virginie Charette, Todd Drumm, and William Goldman

*dvi**pdf**ps*

in*Recent developments in pseudo-Riemannian Geometry: Proceedings of the Special Semester "Geometry of pseudo-Riemannian manifolds with application to physics", Erwin Schrödinger Insitute, Vienna, Sept - Dec 2005*(eds. D. Alekseevsky and H. Baum) in ESI-Series on Mathematics and Physics*Actions of noncompact semisimple groups on Lorentz manifolds*, with Mohamed Deffaf and Abdelghani Zeghib

*dvi**pdf**ps*

*Geometric and Functional Analysis***18**no. 2 (2008) 463-488*Isometric actions of Heisenberg groups on compact Lorentz manifolds*

*dvi**pdf**ps*

*Geometriae Dedicata***126**no. 1 (2007) 131-154

- Connections for Women: Dynamics on Moduli Spaces of Geometric Structures (co-organizer) Mathematical Sciences Research Insitute, January 2015
- Dynamics on Moduli Spaces of Geometric Structures Mathematical Sciences Research Insitute, January-March, 2015
- AMS Eastern Sectional Meeting (co-organizer of Special Session on Differential Geometry and Mathematical Physics), Halifax, NS, October 2014
- CUNY Graduate Center Geometry and Topology Seminar, April 2014
- Université Nice Sophia-Antipolis Séminaire d'algèbre, topologie et géométrie, April 2014
- Université Paris-Sud XI Séminaire Géométrie Topologie Dynamique, April 2014
- Asymptotic Properties of Groups Institut Henri Poincaré, March 2014
- GEAR Network Retreat (co-organizer) College Park, MD, March 2014
- Australian National University Colloquium, February 2014
- University of Illinois, Chicago Colloquium, February 2014
- Nebraska Conference for Undergraduate Women in Mathematics (panelist) Lincoln, NE, January-February 2014
- The 34th Winter School in Geometry and Physics Srní, Czech Republic, January 2014
- University of Wisconsin Colloquium, January 2014
- Winston Churchill High School Mu Alpha Theta Math Honor Society lunchtime talk, November 2013
- University of Pennsylvania Geometry-Topology Seminar, October 2013
- Workshop on Exotic Geometric Structures Institute for Computational and Experimental Research in Mathematics, September 2013
- New Directions
in Exterior Differential Systems: in honor of Robert Bryant's 60th
birthday Estes Park, CO, July 2013
- Workshop on
Cartan Connections, Geometry of Homogeneous Spaces, and Dynamics (co-organizer)
Erwin Schrödinger Institute, July, 2011

Abstracts for week 2, with some links to slides

I am a guest editor for the ensuing special issue of the*Central European Journal of Mathematics*