Thomas Willwacher

RFIG lamps: interacting with a self-describing world via photosensing wireless tags and projectors

This paper describes how to instrument the physical world so that objects become self-describing, communicating their identity, geometry, and other information such as history or user annotation. The enabling technology is a wireless tag which acts as a radio frequency identity and geometry (RFIG) transponder. We show how addition of a photo-sensor to a wireless tag significantly extends its functionality to allow geometric operations - such as finding the 3D position of a tag, or detecting change in the shape of a tagged object. Tag data is presented to the user by direct projection using a handheld locale-aware mobile projector. We introduce a novel technique that we call interactive projection to allow a user to interact with projected information e.g. to navigate or update the projected information.The ideas are demonstrated using objects with active radio frequency (RF) tags. But the work was motivated by the advent of unpowered passive-RFID, a technology that promises to have significant impact in real-world applications. We discuss how our current prototypes could evolve to passive-RFID in the future.

M. Kontsevich’s graph complex and the Grothendieck–Teichmüller Lie algebra

We show that the zeroth cohomology of M. Kontsevich’s graph complex is isomorphic to the Grothendieck–Teichmüller Lie algebra

Quadric Transfer for Immersive Curved Screen Displays

\mathfrak {{grt}}_1

Equivalence of formalities of the little discs operad

grt1. The map is explicitly described. This result has applications to deformation quantization and Duflo theory. We also compute the homotopy derivations of the Gerstenhaber operad. They are parameterized by

Frequency analysis of transient light transport with applications in bare sensor imaging

\mathfrak {{grt}}_1

The Oriented Graph Complexes

grt1, up to one class (or two, depending on the definitions). More generally, the homotopy derivations of the (non-unital)