# Geometry, Topology and Dynamics Seminar

The seminar aims to introduce research topics in geometry, topology and dynamics and its interactions with other sciences on a simple level. Some topics are discussed over a two ot three-week period led by the same speaker (as a mini-course). Anyone interested in mathematics is welcome to attend.

#### Winter 2019

The seminar will meet regularly on Wednesday and occasiionally on another day of the week. The time and location is 16:00-17:00 at Lab 3, B700 unless otherwise noted.

Date | Speaker | Title |

16 January | Hirofumi Sasahira (Kyushu University) | The Seiberg-Witten equations and topology |

22 January (Tuesday 15:00-16:00) | Tadayuki Watanabe (Shimane University) | Preliminary lecture I: Goussarov-Habiro's theory of graph surgery |

23 January (11:00-12:00, unit space B662) | Tadayuki Watanabe (Shimane University) | Preliminary lecture II: Kontsevich's characteristic classes (Chern-Simons perturbation theory configuration space integral) |

23 January | David Gabai (Princeton University) | The General 4 dimensional Light Bulb Theorem |

24 January (Thursday 16:00-17:00) | Tadayuki Watanabe (Shimane University) | Some exotic nontrivial elements of the rational homotopy groups of Diff(S^4) |

29 January (Tuesday 15:00-16:00) | Brian Seguin (Loyola University Chicago) | On the nonlocal curvature of surfaces and curves |

30 January | Shinpei Baba (Osaka University) | Neck-pinching of CP^1-structures |

18 February (Monday 16:00-17:00) | Harrison Chapman (Colorado State University) | Alternating knots are rare |

20 February | Jennifer Schultens (UC Davis) | |

21 February (Thursday 16:00-17:00) | Michael Kapovich (UC Davis) | |

25 February (Monday 16:00-17:00) | Dan Romik (UC Davis) | Viazovska's work on the sphere packing problem and some recent developments in number theory |

18 March (Monday 16:00 - 17:00) | Stephan Tillmann (University of Sydney) | Character varieties, ideal points and actions on trees |

19 March (Tuesday 15:00 - 16:00) | Stephan Tillmann (University of Sydney) | Essential surfaces detected by the character variety |

20 March | Ben Burton (University of Queensland) | Topology on tiny machines: logspace and finite-state complexity |

22 March (Friday 17:00 - 18:00) | Stephan Tillmann (University of Sydney) | Tropical geometry, normal surfaces and the character variety |

26 March (Tuesday 15:00 - 16:00) | Bernd Krauskopf (University of Auckland) | Global manifolds and the transition to chaos in the Lorenz system |

27 March | Hinke Osinga (University of Auckland) | Robust chaos: a tale of blenders, their computation, and their destruction |

23 May (Thursday 13:00-14:00 B715) | Hokuto Konno (Riken) | Non-smoothable bundles and gauge theory for families |

#### Fall 2018

The seminar will meet at 4:00 pm on Wednesday at Lab 3, B700 unless otherwise noted.

Date | Speaker | Title |

2 October (Tuesday, 11:00-12:00, Lab 3 B717) | Makoto Narita (Okinawa National College of Technology) | Spacetime Singularities -An Introduction- |

24 October | Kenta Hayano (Keio University) | On Diagrams of Simplified Trisections and Mapping Class Groups |

31 October | Osamu Saeki (Kyushu University) | Unlinking singular locus from regular fibers and its application to submersions |

7 November | Kazuto Takao (Kyoto University) | Morse functions and singularities of product maps |

8 November (Thursday, 3-4 pm, unit space B662 in Lab 2) | Shinobu Hikami (OIST) | Topological gravity and intersection theory followed by math/math physcis tea (open to all) |

14 November | John Loftin (Rutgers University, Newark) | Neck pinch singularities in the geometry of surfaces |

5 December | Scott Carter (University of South Alabama) | Ribbon and string representations of finite subgroups of SU(2) |

#### Summer 2018

The seminar will meet at 3:00 pm on Wednesday at Lab 3, B700 unless otherwise noted.

Date | Speaker | Title (click for abstract) |

9 May |
Linling Ru (OIST) Motoko Kato (Tokyo University) |
(1) A suspension flow with a Plykin attractor (2) On groups whose actions on finite-dimensional CAT(0) spaces have global fixed points (Lab2, B662) |

21 May | Jessica Purcell (Monash University) | Cusp shape and tunnel number (part 1) |

22 May | Jessica Purcell (Monash University) | Cusp shape and tunnel number (part 2) |

23 May | Jessica Purcell (Monash University) | Cusps and alternating knots |

24 May |
Joel Hass (UC Davis) |
Comparing shapes of genus zero [public lecture, no topology background expected] (4-5pm, Room B250) |

30 May |
Anastasiia Tsvietkova (OIST) | |

6 June | Josh Howie (Monash University) | Coiled Surfaces And The Slope Conjectures |

13 June-August 1 | Conferences/Research Travel/Summer Break | |

1 August, (Thursday) | Dale Koenig (OIST) | Computational complexity and knot theory |

9 August (Thursday) | Robert Tang (OIST) | Solving word problems in finitely presented groups |

16 August (Thursday) | Tirasan Khandhawit (OIST) | Stable Homotopy and Differential Topology |

#### Spring 2018