BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Isaiah Osborne (Middle Tennessee State University) DTSTART:20230622T141500Z DTEND:20230622T160000Z DTSTAMP:20260422T065846Z UID:CJCS/121 DESCRIPTION:Title: S ign Invertibility of Graphs\nby Isaiah Osborne (Middle Tennessee State University) as part of Copenhagen-Jerusalem Combinatorics Seminar\n\n\nAb stract\nA graph is considered invertible if its adjacency matrix represent ation is also invertible. While the process of finding invertible graphs i s fairly simple\, we can also study a subfamily of invertible graphs that are sign-invertible. For our research\, a graph is considered sign-inverti ble if its graph’s adjacency matrix is invertible and its inverse is a m atrix with each entry belonging to {−1\, 0\, 1}. While the idea of sign- invertibility was first introduced in the 1980s by Bucky\, Doty and Harary \, there has been little progress toward finding a complete categorization of sign invertible graphs since then\, until Kalita and Sarma studied a s ub-family of unicyclic graphs. We provided a complete categorization of bo th invertible and s-invertible graphs with at most two cycles and a partia l characterization of sign-invertible cactus graphs.\n LOCATION:https://researchseminars.org/talk/CJCS/121/ END:VEVENT END:VCALENDAR