Oral Presentations and Performances: Session I

Author Information

Project Type

Presentation

Project Funding and Affiliations

Mathematical Sciences

Faculty Mentor’s Full Name

Mark Kayll

Faculty Mentor’s Department

Mathematical Sciences

Additional Mentor

Michael Severino, mseverino@fvcc.edu

Abstract / Artist's Statement

The infamous four-color problem (4CP) dates back to 1852 and asks whether four colors suffice to color a map so that countries sharing a border receive distinct colors. This year marks the 50th anniversary of the problem's resolution. The 4CP inspired a bountiful collection of mathematics in the subject now known as "graph theory." A graph models any sort of network such as the Internet, transportation systems, and the neural networks that underpin modern AI. Graphs consist of two components: "vertices" and "edges." We visualize the vertices as dots on a page and the edges as lines connecting pairs of dots. Analogous to the 4CP, coloring the vertices of a graph means to assign each vertex a color so that any two vertices sharing an edge receive distinct colors. Given enough colors, it might be possible to color a graph in numerous ways. In honor of the 4CP, this project seeks to count those ways, taking into account the underlying symmetries. For example, consider a beaded necklace where the beads are vertices and adjacent beads correspond to edges. With colored beads, that necklace may look the same after a rotation or a flip. We want to count the number of distinguishable necklaces. Somewhat surprisingly, a tool from algebra plays a crucial role in determining the desired count.

Category

Physical Sciences

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Apr 17th, 9:30 AM Apr 17th, 9:45 AM

Graph colorings up to symmetries

UC 329

The infamous four-color problem (4CP) dates back to 1852 and asks whether four colors suffice to color a map so that countries sharing a border receive distinct colors. This year marks the 50th anniversary of the problem's resolution. The 4CP inspired a bountiful collection of mathematics in the subject now known as "graph theory." A graph models any sort of network such as the Internet, transportation systems, and the neural networks that underpin modern AI. Graphs consist of two components: "vertices" and "edges." We visualize the vertices as dots on a page and the edges as lines connecting pairs of dots. Analogous to the 4CP, coloring the vertices of a graph means to assign each vertex a color so that any two vertices sharing an edge receive distinct colors. Given enough colors, it might be possible to color a graph in numerous ways. In honor of the 4CP, this project seeks to count those ways, taking into account the underlying symmetries. For example, consider a beaded necklace where the beads are vertices and adjacent beads correspond to edges. With colored beads, that necklace may look the same after a rotation or a flip. We want to count the number of distinguishable necklaces. Somewhat surprisingly, a tool from algebra plays a crucial role in determining the desired count.