Sage Days 74: Differential geometry and topology

Sage Days 74 will take place on May 30 - June 2, 2016 at the Workshop Center (CIAS) of Observatoire de Paris, located in Meudon, near Paris, France.

Registration

Registration is free and now open. Contact Eric (eric.gourgoulhon@obspm.fr) and Travis (tscrimsh@umn.edu) to register.

Schedule

The morning sessions will take place in Salle de Conférences du Château (CIAS building) and the afternoon sessions will be held in various rooms of CIAS.

Projects

Here is a list of possible projects. Feel free to add your own to the list.

• SageManifolds inclusion into Sage (cf. #18528) (Travis, Eric)

• Lie algebras #14901 and implement their relationship with manifolds. (Travis)

• CW/Cube complexes by generalizing the manifold classes. (Travis)
• Computation of geodesics on pseudo-Riemannian manifolds. (Eric)

• Include the sage.geometry.riemannian_manifolds (i.e. parametrized surfaces) into the more general framework of SageManifolds (Claudia, Eric)

• Experiment plotting possibilities with OpenGL (nice stuff from SnapPy!) and more... for rendering in browser there is the WebGL javascript library that is supported by most browsers.

• Improve persistent homology. (Travis, John)
• Simplicial sets. (Co)simplicial objects in various categories. (John)

• Incorporation of Kenzo? (see Repackaged in a sane way Kenzo)

• Improve/Implement knot theory in Sage (cf. #17030 #20509)... and link it with Snappy? (Travis, Miguel, Eric?, Nathan?)

• Implement more (co)homology theories (e.g., De Rham cohomology).
• Implement methods for computing homotopy groups.
• Tropical curves/geometry.
• Implement Lie groups and related geometric objects such as Schubert cells.
• Implement geometric crystals.

• Implement hyperbolic space for dimensions > 2.

• Implement common metric spaces; for example, L^p spaces.

• Combine/standardize features of the hyperbolic plane with SageManifolds.

• Sage development workflow (cf. https://wiki.sagemath.org/CodeSharingWorkflow)

• Improve/upgrade CHomP and its interface (cf. #15202) (Travis, John, Volker?)

• Clean up simplicial complex code (some easy cleanups like allowing the _enlarged cache to persist in add_face, also generally examine the code) (Travis, John)

• From Nathan's talk: Make SnapPy a Sage package (#20739), Sage attach and Tkinter (#15152), Modernize CyPari (see #20238), Modularization of some parts of SageMath kernel for use in stand-alone Snappy.

• Relative simplicial complexes. (Jeremy)
• Exchanging information between 2D and 3D manifolds. (Vincent)

• From Mark Bell's talk: confusing documentation of the .n method (#13055), accurate numerical approximation, pushout for different number fields (#20746), the bitwise ~ incompatible between Python and Sage integers

There is also the SageMathCloud project page available for collaborations:

https://cloud.sagemath.com/projects/bc98ddf4-68da-49db-8986-90c80b24daa3/files/

Some of the work done within Sage

• List of tickets written and/or reviewed during these Sage days

Details

Lodging

We recommend to book a room in some hotel in Paris, in Montparnasse area (14th arrondissement). In particular, we recommend the

• Hôtel du Maine (**) (109 euros/night, including breakfast)

Other hotels are

• Hôtel Denfert Montparnasse (**) (approx. 110 euros/night, including breakfast)

• Hôtel Ariane Montparnasse (***) (approx. 130 euros/night, including breakfast)

• Hôtel du Parc (***) (approx. 170 euros/night, including breakfast)

If you prefer to stay in Meudon, at a walking distance (25 min) from the Workshop Center (CIAS), see

• Hôtel Ibis Budget Meudon (**) (approx. 80 euros/night, including breakfast)

For a larger choice, see this list of convenient hotels from LESIA/Observatoire de Paris.

NB: since May/June is a high touristic season in Paris, it is recommended to book a room as soon as possible!

Transportation

Meudon is located at 10 min by train from Montparnasse station in Paris. All hotels listed above are located at a walking distance from Montparnasse station. A system of car shuttle will be organized from Meudon station to the Workshop Center (CIAS).

If you plan instead to come by your own, please follow these access instructions (click on the map to enlarge it; the CIAS is located in BAT. 9).

Funding

European participants receiving some OpenDreamKit funding for conferences/workshops are expected to use it to cover their expenses.

Support

• Observatoire de Paris: CIAS and Federative Action Gravitation et physique fondamentale (GPhys)

• Horizon 2020 European Research Infrastructure project OpenDreamKit

• ANR Project Analyse Asymptotique en Relativité Générale

Speakers

• Mark Bell (University of Illinois, Urbana-Champaign)
• Volker Braun (Berlin)
• Marc Culler (University of Illinois, Chicago)
• Vincent Delecroix (University of Bordeaux)
• Nathan Dunfield (University of Illinois, Urbana-Champaign)
• Patrick Hooper (City College of New York)
• Marcin Kostur (University of Silesia, Katowice)
• Jeremy L. Martin (University of Kansas, Lawrence)
• John Palmieri (University of Washington, Seattle)
• Thibaut Paumard (Observatoire de Paris)
• Nicolas Thiéry (University Paris Sud)
• Frédéric Vincent (Observatoire de Paris, France)

Participants

• Michal Bejger (N. Copernicus Astronomical Center, Warsaw, Poland)
• Mark Bell (University of Illinois, Urbana-Champaign, USA)
• Volker Braun (Berlin, Germany)
• Léo Brunswic (University of Avignon, France)
• Marc Culler (University of Illinois, Chicago, USA)
• Vincent Delecroix (University of Bordeaux, France)
• Jeroen Demeyer (Ghent University, Belgium / University Paris Sud, France)
• Nathan Dunfield (University of Illinois, Urbana-Champaign, USA)
• Anastasia Golubtsova (Bogoliubov Laboratory of Theoretical Physics, Dubna, Russia)
• Eric Gourgoulhon (Observatoire de Paris, France)
• Claudia Grabs (University of Potsdam, Germany)
• Patrick Hooper (City College of New York, USA)
• Marcin Kostur (University of Silesia, Katowice, Poland)
• Ronja Kuhne (University of Warwick, UK)
• Samuel Lelièvre (University Paris Sud, France)
• Alba Malaga Sabogal (Aix-Marseille Université, France)
• Marco Mancini (Observatoire de Paris, France)
• Jeremy L. Martin (University of Kansas, Lawrence, USA)
• Thomas Morzadec (University Paris Sud, France)
• John Palmieri (University of Washington, Seattle, USA)
• Thibaut Paumard (Observatoire de Paris, France)
• Bonnie Saunders (University of Illinois, Chicago, USA)
• Travis Scrimshaw (University of Minnesota, USA)
• Nicolas Thiéry (University Paris Sud, France)
• Artur Trzesiok (Poland)
• Frédéric Vincent (Observatoire de Paris, France)

Remote:

• Miguel Angel Marco Buzunariz (University of Zaragoza, Spain)

Group photo

Credit: Sylvain Cnudde

Organizers

• Eric Gourgoulhon (LUTH, Observatoire de Paris)
• Nicole Letourneur (CIAS, Observatoire de Paris)
• Marco Mancini (LUTH, Observatoire de Paris)

• Benoît Pilorget (OpenDreamKit)

• Travis Scrimshaw (University of Minnesota)