For other people with the same name, see Robert Berger.
Robert Berger (born 1938) is an applied mathematician, known for discovering the first aperiodic tiling[1] using a set of 20,426 distinct tile shapes.
Contributions to tiling theory
The unexpected existence of aperiodic tilings, although not Berger's explicit construction of them, follows from another result proved by Berger: that the so-called domino problem is undecidable, disproving a conjecture of Hao Wang, Berger's advisor. The result is analogous to a 1962 construction used by Kahr, Moore, and Wang, to show that a more constrained version of the domino problem was undecidable.[2]
Berger's work on tiling was published as "The Undecidability of the Domino Problem" in the Memoirs of the AMS in 1966.[4] This paper is essentially a reprint of Berger's 1964 dissertation at Harvard University.[5]
In 2009, a paper by Berger and other Lincoln Laboratories researchers, "Wafer-scale 3D integration of InGaAs image sensors with Si readout circuits", won the best paper award at the IEEE International 3D System Integration Conference (3DIC).[6] In 2010, a CMOSinfrared imaging device with an analog-to-digital converter in each pixel, coinvented by Berger, was one of R&D Magazine's R&D 100 Award recipients.[7]