Local varying-alpha theories

Central and Local Limit Theories in Markov Dependent Random Variables

Extra Dimensions and Varying Alpha

I review recent constraints on and claimed detections of a time-varying fine-structure constant α. Our results are consistent with no variation in α from the epoch of recombination to the present day, and restrict any such variation to be less than about 4%. The forthcoming MAP and Planck experiments will be able to break most of the currently existing degeneracies between α and other cosmologi...

New Constraints on Varying Alpha

I briefly present some current theoretical motivations for time or space variations of the fundamental constants of nature and review current key observational results. I focus on the fine-structure constant, and particularly on measurements using quasars and the cosmic microwave background. I also compare various observational results to the simplest model-building expectations .

Local theories of inheritance

Inheritance networks are not expressive enough to capture all intuitions behind inheritance. Hence, a number of signiicantly diierent semantics have been proposed. Here, a family of local theories of inheritance is presented that are conceptually simple and computationally tractable. A general model-theoretic framework for specifying direct semantics to networks and clarifying relationships amo...

New varying speed of light theories

We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying c, dispelling the myth that the constancy of c is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally L...