Recent content by George Jones

  1. George Jones

    I Beginner question about tensor index manipulation

    I find it to be fairly standard, but maybe this is because this is how I learned it all those decades ago. But, what do these symbols mean, and from where does the relation come?
  2. George Jones

    A Construction of real gamma matrices

    Think of it like this: $$\{\sigma^{\mu},\sigma^{\nu} \} = 2 \eta^{\mu \nu} I,$$ where ##I## is the ##2 \times 2## identity matrix, and the ##\eta^{\mu \nu}## are the components of the ##3 \times 3## matrix ##\eta = \mathrm{diag}(-1,1,1)##.
  3. George Jones

    Something to help your elderly parents with their television

    Nope. :smile: I don't have a cell phone. I tell my classes "If i had a cell phone, my partner could get a hold of me."
  4. George Jones

    Something to help your elderly parents with their television

    I don't have a remote for my TV. I guess that's because I don't have a TV.
  5. George Jones

    I Physical consequences of the metric signature

    I do not have time to read this long paper, but the abstract is fascinating. Doesn't this say that nature could possibly favour one Pin group over the other? Also, note that one of the authors is Cecile Dewitt-Morette.
  6. George Jones

    Computer languages tend to be transient

    I wrote my first programs (which used Fortran) without typing. I posted the following in a restrict forum, so I'll share it more widely here. My "back in the day" story. Fortran was my first progamming language, which I leaned in two high school computer science courses from '76 to '78. My...
  7. George Jones

    Can you name someone that pulled off a certain impossible feat academically?

    My wife being one of them. My wife has four degrees, each from a different Canadian university, She does not have a Ph.D., and she has four degrees only because of changing career goals, physics -> engineering-> teaching. She has a B.Sc. in Physics (York), an M.Sc. in Physics (Windsor), and...
  8. George Jones

    Computer languages tend to be transient

    Interesting video on evolving popularity of computer languages:
  9. George Jones

    B Questions about the Curvaton particle

    Phys. Rev. D 2014 https://arxiv.org/abs/1403.4591 Phys. Rev. D 2018 https://arxiv.org/abs/1712.05364 Phys. Rev. D 2020 https://arxiv.org/abs/1911.07082 Phys. Rev. D is a high-impact, high-quality research journal.
  10. George Jones

    Help please with this integral involving an inverse trig function

    One way to avoid this is to note (by, e.g., looking at the graph) that the integrand is even about ##\pi##. It is easily shown algebraically that the integrand evaluated at ##\pi - x## is the same as the integrand evaluated at ##\pi + x##. Consequently, ##\int_0^{2\pi} = 2 \int_0^{\pi}##.
  11. George Jones

    Help please with this integral involving an inverse trig function

    I haven't lookd carefully at this, but doesn't $$\int_\pi ^ {2\pi} \frac{dx}{3 + \cos x} = \frac{1}{\sqrt{2}} \tan^{-1} u|_{-\infty}^0 = \frac{1}{\sqrt{2}} \left[0 - \left( -\frac{\pi}{2} \right)\right]$$
  12. George Jones

    Old topic, different look, maybe (Money = work/knowledge )

    I know how to do this! Find a set of apples and oranges. Take the free vector space on this set of apples and oranges. Now apples and oranges can be mixed, i..e, it is possible to take linear combinations of apples and oranges.
  13. George Jones

    Does this QM experiment show that science is doomed?

    begin thead answer question in thead's title no end thead
  14. George Jones

    Quantum Books on Quantum Mechanics

    At about the level of Griffiths, there is "QUANTUM MECHANICS A Paradigms Approach" by David McIntyre. This book has more emphasis on Dirac notation than does Griffiths, which I like.
  15. George Jones

    Foundations Is Yuri Manin's A Course in Mathematical Logic generally unsound?

    On what page(s) of the second edition is von Neumann's impossibility proof discussed.
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