Are Particles and Anti-Particles Identical in LQG and String Theory?

  • Thread starter wolram
  • Start date
  • Tags
    Particles
In summary, the conversation discusses the properties of particles and anti-particles in LQG and String theory. It is noted that LQG is primarily focused on spacetime geometry and not a theory of matter, though matter can be included in models. The idea is raised that LQG may provide clues about matter symmetries and interactions with space, but this is not yet fully developed. One person suggests emailing an expert in LQG phenomenology to discuss the possibility of observable effects. The original idea is acknowledged as possibly being unclear, but the person plans to continue thinking about it and may rephrase their question.
  • #1
wolram
Gold Member
Dearly Missed
4,446
558
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.
 
Physics news on Phys.org
  • #2
wolram said:
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.

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:
  • #3
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.
 
  • #4
wolram said:
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.

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 don't 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 doesn't reply to your email, what's lost?
I don't see anything wrong with writing some LQG phenomenologist

a prominent leader in the QG phenomenology business is Giovanni Amelino Camelia, if Parampreet Singh doesn't 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:
  • #5
PS wolram, I don't 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 won't form properly into
understanding, i will give it some more thought, and hopefully
be able to refrase the question.
Thank Marcus.
 

1. What are particles and anti-particles?

Particles and anti-particles are fundamental units of matter that make up the universe. They are tiny, subatomic particles that have mass and carry various properties such as electric charge and spin.

2. How are particles and anti-particles related?

Particles and anti-particles are related through a concept called "charge conjugation." This means that for every particle, there is an anti-particle with the same mass but opposite charge. For example, the anti-particle of an electron (a negatively charged particle) is a positron (a positively charged particle).

3. What happens when a particle and an anti-particle collide?

When a particle and an anti-particle collide, they annihilate each other and release a burst of energy in the form of photons. This process is known as "pair production" and is commonly observed in high-energy particle collisions.

4. Can particles and anti-particles coexist?

Particles and anti-particles can coexist in certain conditions, but they will eventually annihilate each other if they come into contact. In the early universe, when the temperature was extremely high, particles and anti-particles existed in equal amounts. As the universe cooled, most of the particles and anti-particles annihilated, leaving behind a small excess of particles that make up the matter we see today.

5. What is the significance of particles and anti-particles in modern physics?

Particles and anti-particles play a crucial role in understanding the fundamental laws of nature. They are essential in theories such as the Standard Model, which describes the interactions between particles, and in understanding the structure of matter and the universe. Additionally, the study of particles and anti-particles has led to advancements in technology, such as medical imaging and particle accelerators.

Similar threads

  • Beyond the Standard Models
Replies
7
Views
1K
  • Beyond the Standard Models
Replies
26
Views
497
  • Beyond the Standard Models
Replies
5
Views
1K
  • Beyond the Standard Models
Replies
3
Views
1K
  • Beyond the Standard Models
Replies
13
Views
1K
  • Beyond the Standard Models
Replies
12
Views
2K
  • Beyond the Standard Models
Replies
6
Views
584
Replies
3
Views
2K
Replies
13
Views
2K
  • Beyond the Standard Models
Replies
1
Views
1K
Back
Top