Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Particles and anti particles

  1. Mar 24, 2005 #1

    wolram

    User Avatar
    Gold Member

    Can someone tell me if particles and anti particles, are considered
    to have the same properties, other than sign reversal, in LQG and
    String theory.
     
  2. jcsd
  3. Mar 24, 2005 #2

    marcus

    User Avatar
    Science Advisor
    Gold Member
    2015 Award
    Dearly Missed

    so far LQG is about spacetime geometry
    and it is not a theory of matter
    people include matter in LQG models, by putting some extra labels on the spin networks, but the matter they include is very basic rudimentary stuff (like e.g. a scalar field) just to have something that can interact with gravity.

    I think the idea here is that you do one thing at a time:
    first get a model of spacetime geometry that works (a quantum replacement for General Relativity)
    and then, when you have that, add matter to it

    so I would not expect LQG to say anything about parity reversal until
    (and if) it is fully developed and checked out as a theory of spacetime geometry. I could be surprised though and it might start providing clues about what matter is and how matter symmetries (like parity reversal) arise and how matter interacts with space----it could, I suppose, start to provide clues about that BEFORE it is complete and the first goal is reached of getting a quantum theory to replace general relativity.
     
    Last edited: Mar 24, 2005
  4. Mar 24, 2005 #3

    wolram

    User Avatar
    Gold Member

    It was just a thought, that if a massive body polarised the local
    field, then because there is a small cp violation between matter
    and anti matter, and that gravity may be granular, that a small
    amount of stress in this local would produce a time difference
    that is due to the quantum nature of gravity.
     
  5. Mar 24, 2005 #4

    marcus

    User Avatar
    Science Advisor
    Gold Member
    2015 Award
    Dearly Missed

    sounds to me like a reasonable line of speculation. I would email some
    academic person like Parampreet Singh a postdoc at penn state
    who is becoming an expert in LQG phenomenology---in analyzing possible observable effects.

    singh@gravity.psu.edu

    he might think the idea is too loony and incoherent to bother with
    but you never know, he might not,
    and he might answer

    any kind of observable effect is at a premium these days and worth at least a few moments of thought

    PS wolram, I dont quite grasp what you are talking about. and you may not fully understand what you are talking about either. but that is not the issue and should not prevent you from pursuing the idea

    it sounds like you are guessing at the possible presence of a LQG signal in the radiation from the accretion disk of a black hole, or in the CMB, or in the cosmic neutrino background when and if we are able to see it---that is, you are guessing about possible traces of LQG in radiation from something with very strong gravity like the bigbang or black holes.

    so, if he thinks your idea is foolish for some reason, what's the harm?
    if he doesnt reply to your email, what's lost?
    I dont see anything wrong with writing some LQG phenomenologist

    a prominent leader in the QG phenomenology business is Giovanni Amelino Camelia, if Parampreet Singh doesnt reply you could write him.

    I personally do not know enough about LQG effects to respond properly
    if you do write one of those guys, be brief----then theyr more apt to answer
     
    Last edited: Mar 24, 2005
  6. Mar 24, 2005 #5

    wolram

    User Avatar
    Gold Member

    PS wolram, I dont quite grasp what you are talking about. and you may not fully understand what you are talking about either.
    ----------------------------------------------------------------------------------
    This is true, i have an idea but it wont form properly into
    understanding, i will give it some more thought, and hopefully
    be able to refrase the question.
    Thank Marcus.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Particles and anti particles
  1. Particle overview (Replies: 8)

  2. SUSY particles (Replies: 6)

  3. What is a particle? (Replies: 51)

  4. Particles in LQG (Replies: 4)

Loading...