## Bay Area Discrete Math Day, Fall 2018

#### Sonoma State Univeristy

#### Darwin Hall, Room 103

#### Saturday, October 20th, 2018

#### 10:00am-5:00pm

Thanks to Andrew Beyer for this BAD Math logo!Do you think you can create a new logo to include SSU and Sac State? Create a new logo and send to one of the BAD organizers (see list below).

The Fall 2018 Bay Area Discrete Math Day (BAD Math Day) will take place on the campus of Sonoma State University ** in Rohnert Park, California on Saturday, October 20th, 2018**, between 10:00am and 5:00pm.

All events will be held in Room 103 Darwin Hall.

** Registration is open until October 5th. See the link below to register. **Lunch is covered for all participants. The first 30 registered will be funded for dinner!

#### Schedule

The talks will begin at 10:00AM on Saturday, October 20th, 2018 and end by 5:00PM.

Arrive at 9:00AM for check in and refreshments!

Time | Speaker | Title | Abstract |
---|---|---|---|

9:00- 10:00am | Welcome and Refreshments | ||

10:00- 10:30am | Nick Dowdall | Is abundance 1 possible? | The abundance function is the cardinal number associated with an integer by subtracting the integer from the sum of its proper divisors. We will take a brief exploration into the world of this function and ask simple questions with surprising and sometimes perplexing results. |

10:45- 11:15am | Emily Clader | Tautological relations on the moduli space of curves | Enumerative geometry is concerned with answering questions like: given five points in the plane, how many ellipses pass through all five of them?,From a modern perspective, these problems are translated into questions about intersection theory on moduli spaces, which, in turn, are encoded in the Chow ring.,I will discuss a particularly important example, the moduli space of curves, and explain some of the tools for studying its Chow ring. |

11:30- 12:30pm | Ellen Veomett | Mathematical Tools to Combat Gerrymandering | Gerrymandering is a term that is used to describe the drawing of district lines in a way that disenfranchises a group of voters. The business of gerrymandering is not new, and various court cases have addressed the illegality of racial gerrymandering. But partisan gerrymandering has proven to be more difficult for the courts to deal with. Many were hoping that the two recent Supreme Court cases on partisan gerrymandering would result in a manageable standard, but the court punted both cases, declining the chance to give a precedent on how future partisan gerrymandering cases could be decided.,In this talk, we'll talk about the flurry of activity and research that has recently surfaced in the mathematical community on this topic.,We'll discuss metrics intended to detect gerrymandering, including recent results on the Efficiency Gap and the declination.,We'll also discuss some statistical techniques that various mathematical groups have used to suggest that districting maps have been drawn with partisan intent. |

12:30-2:00pm | Lunch: Darwin Lobby and Patio, Catered by Panera | ||

2:00- 2:30pm | Thomas McConville | Algebras and lattices from partial triangulations | Finite dimensional associative algebras come equipped with a wide array of interesting structures and bijective correspondences. For some algebras, these correspondences turn into familiar bijections among Catalan objects such as triangulations of a polygon and noncrossing partitions. In this talk, I will explain an analogous story for a family of gentle algebras in which the Catalan objects are replaced by partial triangulations and noncrossing tree partitions, respectively. This is based on joint work with Alexander Garver. |

2:45- 3:15pm | Maryam Farahmand | The arithmetic of graph labeling polynomials | Graph theory is abundant with attractive-- and attractively simple to state-- open problems. In this talk, we address a long-standing and still-wide-open conjecture, the Antimagic Graph Conjecture, and the technique we proposed, Partially Magic Labelings, to attack this conjecture. |

3:15- 3:45pm | Break | ||

3:45pm- 4:45pm | Jeffrey Lagarias | Polynomial Splitting Measures and some interesting representationsof the symmetric group | This talk starts from a number theory counting problem concerning the probabilities for various factorizations of squarefree degree n monic polynomials over finite fields Fp. These probabilities, as a function of p (for fixed splitting type), interpolate as rational functions of a variable z, which are Laurent polynomials. Identifying splitting types with conjugacy classes of the symmetric group Sn allows these probabilities to be viewed as class functions on Sn. One can then ask: "what happens at z = 1?" Another question concerns: are these class functions interesting if viewed as characters of rational representations of Sn? Experimental work showed nice patterns, indicating a yes answer. The talk will describe an interesting answer, found in joint work with Trevor Hyde. In the squarefree case the individual Laurent coefficients when rescaled are characters of (virtual) representations of the symmetric group Sn, arising from part of the cohomology of the pure braid group, viewed as an Sn-module. |

5:30pm | Dinner at Honey Korean BBQ and other local restaurants |

#### Food

Lunch (catered sandwiches), coffee, and snacks will be provided for free at the conference. Dinner will be held at a restaurant nearby for the first 30 participants. Others will be encouraged to dine together and other nearby establishments.

#### Registration

Click here for the registation form. Registration will be open until **Friday, October 5th**. There is no conference fee, register today!

#### Poster

Click here for a printable version of postcards for the event.

#### Directions and parking

Click here for directions to Sonoma State. Parking is $8 for the day. To obtain a parking pass and a campus map, please stop by either of the Parking Information Centers on campus upon your arrival.

Please talk with your local BAD Math Organizer about carpooling, or e-mail Natalie Hobson (hobsonn@sonoma.edu) if you’re interested in carpooling and you don’t have a natural group to join.

#### Funding

The Fall 2018 BAD Math Day is generously sponsored by the Sonoma State University’s School of Science and Technology, SSU Deparatment of Mathematics and Statistics, Elsevier, and the American Institute of Mathematics.

#### About BAD Math Days

BAD Math Days are one-day meetings aimed at facilitating communication between researchers and graduate students of discrete mathematics around the San Francisco Bay Area. These days happen twice a year and strive to create an informal atmosphere to talk about discrete mathematics. The term “discrete mathematics” is chosen to include at least the following topics: Algebraic and Enumerative Combinatorics, Discrete Geometry, Graph Theory, Coding and Design Theory, Combinatorial Aspects of Computational Algebra and Geometry, Combinatorial Optimization, Probabilistic Combinatorics, and Combinatorics in Mathematical Physics. All are welcome to attend!

#### The BAD Math Organizing Committee

- Federico Ardila, San Francisco State University
- Jay Cummings, Sacremento State University
- Elizabeth Gross, San Jose State University
- Natalie Hobson, Sonoma State University
- Nicolette Meshkat, Santa Clara University
- Carol Meyers, Lawrence Livermore National Laboratory
- Christopher O’Neill, University of California, Davis
- Rick Scott, Santa Clara University
- Khrystyna Serhiyenko, University of California, Berkeley
- Ellen Veomett, Saint Mary’s College of California
- Ruriko Yoshida, Naval Postgraduate School

### Mission Statement

We invite and welcome students from all educational and cultural backgrounds to join us in creating an active, collaborative learning community that celebrates the complexity, beauty, and applicability of mathematics and statistics.

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