Natural Science Forum / Physics / Research / February 2010

Problem: An electron and a positron annihilate to produce a pair of
photons which move in two specific directions. Now the question is
what really transports the information of annihilation(from the point
of annihilation)? If the photons are the agents transporting

It would be greatly appreciated if this announcement could be
shared with individuals whose research interests include
scientific computing.  Thanks.
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A question about neutrino oscillations - what justifies the use of
energy eigenstates in calculating the oscillation rate?
The derivation of the oscillation rate as proportional to the mass-
squared-difference relies on two things: (a) the neutrino energy is

During the past several months there have been discussions here
regarding path integration and the extent to which it does, or does,
not, provide a rigorous foundation for developing quantum field theory.
Peter Enders just pointed me toward the book by Hagen Kleinert, "Path

In the separate thread "Quantum Field Theory: The Big, Simple
Picture?" which I earlier initiated, an excellent discussion emerged,
largely involving Dr. Neumaier, Igor, X-Phy, and a few other folks,
about path integration and its virtues and limits.

======= Moderator's note ==========================================
Disclaimer: The following posting and advertised paper contradicts the
standard analysis of relativistic classical (and quantum) field theory
based on Noether's theorem and representation theory of the Poincare ...

I have been trying to find a generalized expression for the multiple
derivatives of a Gaussian.  Gaussian functions of course have many
application in physics and math, and high order derivatives of this
Gaussian typically are involved in generating Green functions.

If one were to take the position that chirality is present in all
observable systems and states even without a measurement or direct
observation - much like temperature, would that necessitate a unique
formulation for a  Lagrangian and Hamiltonian?

[[Mod. note --
I take it that "FTU" abbreviates "fine-tuned universe"
and "AP" abbreviates "anthropic principle".
-- jt]]

I have a few questions about the so-called "heat kernel" discussed
in http://en.wikipedia.org/wiki/Dirac_delta_function#Semigroups.
This article suggests that the heat kernel (eps=epsilon):
eta_eps(x) = (1/sqrt(2pi eps)) exp[-.5 x^2/eps]   (1)

On Jan 31, 4:24 pm, "Richard D. Saam" <rds...@att.net> wrote
(In relation to nuclear reaction rates for BBN)
at http://groups.google.com/group/sci.physics.research/msg/8d645cadca3e2786?dmode=source:

At the Cosmic Variance Blog someone posted a comment in the form of a
question: "Is spacetime a 4-D manifold?"
It reminded me of Einstein's comment that the idea of spacetime
independent of matter/objects was dubious, at best.