Entropic Time

The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.Comment: Presented at MaxEnt 2010, the 30th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering (July 4-9, 2010, Chamonix, France

Unfoldings and Deformations of Rational and Logarithmic Foliations

We study codimension one foliations in projective space \PP^n over \CC by looking at its first order perturbations: unfoldings and deformations. We give special attention to foliations of rational and logarithmic type. For a differential form \omega defining a codimension one foliation, we present a graded module \UU(\omega), related to the first order unfoldings of \omega. If \omega is a generic form of rational or logarithmic type, as a first application of the construction of \UU(\omega), we classify the first order deformations that arise from first order unfoldings. Then, we count the number of isolated points in the singular set of \omega, in terms of a Hilbert polynomial associated to \UU(\omega). We review the notion of regularity of \omega in terms of a long complex of graded modules that we also introduce in this work. We use this complex to prove that, for generic rational and logarithmic foliations, \omega is regular if and only if every unfolding is trivial up to isomorphism.Comment: Final version. 25 page

Geometry from Information Geometry

We use the method of maximum entropy to model physical space as a curved statistical manifold. It is then natural to use information geometry to explain the geometry of space. We find that the resultant information metric does not describe the full geometry of space but only its conformal geometry -- the geometry up to local changes of scale. Remarkably, this is precisely what is needed to model "physical" space in general relativity.Comment: Presented at MaxEnt 2015, the 35th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering (July 19-24, 2015, Potsdam NY, USA

Jet energy calibration at the LHC

Jets are one of the most prominent physics signatures of high energy proton proton (p-p) collisions at the Large Hadron Collider (LHC). They are key physics objects for precision measurements and searches for new phenomena. This review provides an overview of the reconstruction and calibration of jets at the LHC during its first Run. ATLAS and CMS developed different approaches for the reconstruction of jets, but use similar methods for the energy calibration. ATLAS reconstructs jets utilizing input signals from their calorimeters and use charged particle tracks to refine their energy measurement and suppress the effects of multiple p-p interactions (pileup). CMS, instead, combines calorimeter and tracking information to build jets from particle flow objects. Jets are calibrated using Monte Carlo (MC) simulations and a residual in situ calibration derived from collision data is applied to correct for the differences in jet response between data and Monte Carlo. Large samples of dijet, Z+jets, and photon+jet events at the LHC allowed the calibration of jets with high precision, leading to very small systematic uncertainties. Both ATLAS and CMS achieved a jet energy calibration uncertainty of about 1% in the central detector region and for jets with transverse momentum pT>100 GeV. At low jet pT, the jet energy calibration uncertainty is less than 4%, with dominant contributions from pileup, differences in energy scale between quark and gluon jets, and jet flavor composition.Comment: Article submitted to the International Journal of Modern Physics A (IJMPA) as part of the special issue on the "Jet Measurements at the LHC", editor G. Dissertor

Never Good Enough: Health Care Workers and the False Promise of Job Training

[Excerpt] I have drawn on several qualitative research projects to compose an account of what the training and education industry for allied health care workers is, and what political (perhaps even ethical) dilemmas it poses. The evidence in the book is drawn from several research projects in which I was involved from 1999 to 2003, each of which examined work in health care, life in the sub-baccalaureate labor market, and the genesis and significance of a health care workforce training industry, albeit from different angles. First was a study of occupational change in three subacute care facilities (essentially a level of care between that of an acute care unit and a nursing home), with the aim of identifying where workers might need training. Second was an evaluation of a communication skills training program at a midsize teaching hospital in the center of one of the city\u27s poorest neighborhoods. The third study focused directly on individual workers and the emergence of the industry to train them, for which I conducted in-depth interviews and observed several sessions of two additional training seminars—a customer service training program at a public hospital and an in-service on communication at one of the city\u27s largest home health care agencies