# Algebraic, Tropical, and Nonarchimedean Analytic Geometry of Moduli Spaces (16w5153)

## Organizers

Matthew Baker (Georgia Institute of Technology)

Melody Chan (Brown University)

David Jensen (University of Kentucky)

Sam Payne (Yale University)

## Objectives

This workshop will bring together leading researchers from three fields that rarely have overlapping conferences: tropical geometry, classical algebraic geometry of moduli spaces, and nonarchimedean analytic geometry. Recent breakthroughs have come from teams of mathematicians with a range of backgrounds spanning these disciplines. We believe that this trend will continue, and we will make a concerted effort to attract experts from all of these fields who are interested in collaborating across disciplines. Also, tropical geometry and nonarchimedean geometry (especially the theory of Berkovich spaces) are relatively young fields, so it will be easy and natural to include a significant number of advanced graduate students and recent PhDs in these areas. Our intended list of participants also includes a few carefully chosen geometric group theorists and topologists who have studied the topology of Outer Space and Teichm\"uller space (closely related to moduli spaces of tropical and algebraic curves [cmv}), and have also indicated an interest in learning about the algebraic and tropical perspectives. Topologist S{\o]ren Galatius, for instance, has already begun a collaboration with organizers Chan and Payne using tropical techniques to compute the homotopy type of the boundary complex and top weight cohomology for moduli spaces of curves with marked points.

**Objective 1.** Bring together experts on moduli spaces from algebraic, tropical, and nonarchimedean geometry to learn the state of the art in each area and develop a shared understanding of what has already been accomplished and the most promising directions for future development.

**Objective 2.** Explore possibilities for employing techniques from tropical and nonarchimedean analytic geometry to make progress on classical problems in algebraic geometry, such as the characteristic numbers of the projective plane, and relations among abelian cycles on the moduli space of curves.

**Objective 3.** Discuss opportunities and technical obstacles to be overcome in extending results connecting algebraic and tropical moduli spaces of curves to moduli spaces of surfaces and higher dimensional objects.

Our intended list of participants combines leading researchers from the algebraic geometry and topology of moduli spaces, nonarchimedean analytic geometry, and tropical geometry with advanced graduate students and recent PhDs working in these areas. The organizers will make special efforts to remind all speakers of the breadth of their audience, and will also ensure a relatively open schedule with ample break time when people can talk about more specialized topics in smaller groups, discuss particular problems of mutual interest, and even start collaborations. We will also supplement the research talks during the day with one or two informal open problem sessions in the evenings.

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