The observer’s ghost: notes on a field space connection

Lecture Notes on Parameters & Ghost State

Notes on the Nested Observers for Hybrid Systems ∗

In this paper a hybrid observer for hybrid systems is presented. The continuous time and the discrete event dynamics are determined in such a way that the observation problem is solved. The observer is built using a nested structure, in which the nesting is due to a refinement of those states corresponding to undecided cases. The continuous dynamics implement an estimator which extracts extra i...

Notes on Fock Space

These notes are intended as a fairly self contained explanation of Fock space and various algebras that act on it, including a Clifford algebras, a Weyl algebra, and an affine Kac-Moody algebra. We also discuss how the various algebras are related, and in particular describe the celebrated boson-fermion correspondence. We finish by briefly discussing a deformation of Fock space, which is a repr...

Field Notes on Field Notes: Informing Technology Support for Biologists

Biology fieldwork generates a wealth of qualitative and quantitative information, an unstructured “bag of data,” requiring substantial labor to coordinate and distill. In the interest of furthering research, we present findings from interviews with 15 biologists and analyses of 13 notebooks. We learned that biologists rely on their notebooks as the primary record of observations, plans, measure...

Notes on de Sitter space

The Lorentz n–group is the group of “isometries” (transformations preserving the inner product) of Minkowski space, fixing 0, and preserving the time direction. This implies that a Lorentz transformation is an linear isomorphism of Rn as a vector space. If, in addition to preserving the time direction, we also preserve space orientation then the group can be denoted SO(1, n − 1). Notice that a ...