# NIU Department of Mathematical Sciences

# Upcoming Colloquia and Seminars

**January 20-23, 2015**

Algebra Seminar: | Wednesday, Jan. 21, 4:15-5:15 p.m. in DU 152 | |

Speaker: | Deepak Naidu | |

Topic: | Classification of Modular Categories
| |

Abstract: | Modular categories are braided fusion categories that satisfy a certain nondegeneracy condition. They give rise to representations of the modular group SL(2, Z), explaining the terminology. They arise in several areas of mathematics and physics, such as representation theory, conformal field theory, operator algebras, and topology. After giving several examples of modular categories, I will discuss the problem of classifying these objects according to their Frobenius-Perron dimension. I will present several classification results, including those for Frobenius-Perron dimensions p^n, pq^n, pqr, and p^2q^2, where n is a positive integer and p, q and r are distinct primes. |

Complex Analysis Seminar: | Tuesday, Jan. 27, 11:00-11:50 p.m. in DuSable 464 | |

Speaker: | Alastair Fletcher | |

Topic: | Structures of the Julia set
| |

Abstract: | The Julia set is the set where the iterates of a function behave chaotically. In this talk, we will discuss what topological structures can arise as Julia sets, and in particular give a construction of a uniformly quasiregular mapping in three dimensions for which the Julia set is a wild Cantor set. Joint work with Jang-Mei Wu (UIUC). |

Applied Math Seminar: | Tuesday, Jan. 27, 11:30-12:20 p.m. in Watson 110 | |

Speaker: | Nathan Krislock | |

Topic: | Semidefinite Optimization and Combinatorial Optimization
| |

Abstract: | During the last two decades, semidefinite optimization has grown into a significant field of research with applications in many diverse areas such as graph theory, distance geometry, combinatorial optimization, low-rank matrix completion, and polynomial optimization. In combinatorial optimization, semidefinite optimization is used to compute high-quality bounds to many difficult (in fact, NP-hard) problems, such as Max-Cut and maximum k-cluster. This has led to the development of state-of-the-art branch-and-bound methods for solving such problems to optimality. |

DeKalb, Illinois 60115 | Regional Sites | Contact Information

Emergency Information | Employment | Maps

© 2013 Board of Trustees of Northern Illinois University.

All rights reserved. Web Site Privacy Policy