







This Week at Physics 

<< Fall 2011  Spring 2012  Fall 2012 >> 
Subscribe to receive email announcements of events 
Events on Tuesday, April 24th, 2012
 Chaos & Complex Systems Seminar
 Adaptive information
 Time: 12:05 pm
 Place: 4274 Chamberlin
 Speaker: Rob Nowak, UW Department of Electrical and Computer Engineering
 Abstract: This talk will discuss the notions of adaptive and nonadaptive information in the context of statistical learning and inference. Suppose that we have a collection of models (e.g., signals, systems, representations, etc.) denoted by X and a collection of measurement actions (e.g., samples, probes, queries, experiments, etc.) denoted by Y. A particular model x in X best describes the problem at hand and is measured as follows. Each measurement action, y in Y, generates an observation y(x) that is a function of the unknown model. This function may be deterministic or stochastic. The goal is to identify x from a set of measurements y_1(x),...,y_n(x), where y_i in Y, i=1,...,n. If the measurement actions y_1,...,y_n are chosen deterministically or randomly without knowledge of x, then the measurement process is nonadaptive. However, If y_i is selected in a way that depends on the previous measurements y_1(x),...,y_{i1}(x), then the process is adaptive. Adaptive information is clearly more flexible, since the process can always disregard previously collected data. The advantage of adaptive information is that it can sequentially focus measurements or sensing actions to distinguish the elements of X that are most consistent with previously collected data, and this can lead to significantly more reliable decisions. The idea of adaptive information gathering is commonplace (e.g., humans and animals excel at this), but outside of simple parametric settings little is known about the fundamental limits and capabilities of such systems. Some preliminary results addressing this situation will be described.
 Host: Sprott
 Add this event to your calendar
 "Physics Today" Undergrad Colloquium (Physics 301)
 The Origin of Matter
 Time: 1:20 pm
 Place: 2223 Chamberlin
 Speaker: RamseyMusolf, University of Wisconsin Department of Physics
 Add this event to your calendar
 High Energy Seminar
 Experimental Muon Physics: an Overview
 Time: 3:00 pm
 Place: 5310 Chamberlin Hall
 Speaker: David Webber, University of Wisconsin Madison
 Abstract: According to the Standard Model of particle physics, muons behave like
heavy electrons which decay only via the weak force. Their properties
make them especially wellsuited to precision measurements of
fundamental parameters of the Standard Model, as well as searches for
physics beyond the Standard Model. Muons have the longest lifetime of
any fundamental particle which still decays, allowing them to form
chemical bound states and probe the structure of the proton.
Additionally, muon decay maximally violates parity, correlating the
decay electron with the muon's spin and enabling measurements of g2.
In this talk, several recent experimental results will be reviewed,
and some upcoming experiments will be presented.  Host: Karsten Heeger
 Add this event to your calendar