Can Lattice Size Changes Reveal the Quantization of Space-Time?

  • Thread starter Thread starter anorlunda
  • Start date Start date
  • Tags Tags
    Lattice Length
anorlunda
Staff Emeritus
Science Advisor
Homework Helper
Insights Author
Messages
11,326
Reaction score
8,750
In elementary particle theory, professor Susskind encourages us to think of space-time as divided into a lattice of cells. We use annihilation and creation operators in the Lagrangian to consume a particle in a cell and to create a new particle in an adjacent cell. Repeated application of Lagrangians cause particles to move. The final step is to take the limit as lattice size approaches zero.

I imagine a delta A-B, where A is the limit as lattice size approaches zero, and B is the limit as lattice size approaches the Plank length. Is such a delta meaningful? If so, does the value of that delta reveal anything about the underlying quantization of space-time?

By the way, it thrills me that there exists a forum such as this where one can post such questions and get illuminating answers. Thank you all for being so generous with your time to assist amateurs struggling to understand.
 
Physics news on Phys.org
I'm not quite sure I understand your delta question, but I can tell you there is an in-the-making quantum theory of gravitation called "canonical quantum gravity," also known as "loop quantum gravity" for historical reasons. This is a quantum theory of spacetime that predicts a spacetime lattice. It is an active area of research, though the underdog of quantum gravity to be sure.
 
Toponium is a hadron which is the bound state of a valance top quark and a valance antitop quark. Oversimplified presentations often state that top quarks don't form hadrons, because they decay to bottom quarks extremely rapidly after they are created, leaving no time to form a hadron. And, the vast majority of the time, this is true. But, the lifetime of a top quark is only an average lifetime. Sometimes it decays faster and sometimes it decays slower. In the highly improbable case that...
I'm following this paper by Kitaev on SL(2,R) representations and I'm having a problem in the normalization of the continuous eigenfunctions (eqs. (67)-(70)), which satisfy \langle f_s | f_{s'} \rangle = \int_{0}^{1} \frac{2}{(1-u)^2} f_s(u)^* f_{s'}(u) \, du. \tag{67} The singular contribution of the integral arises at the endpoint u=1 of the integral, and in the limit u \to 1, the function f_s(u) takes on the form f_s(u) \approx a_s (1-u)^{1/2 + i s} + a_s^* (1-u)^{1/2 - i s}. \tag{70}...
Back
Top