Can there be a four dimensional world ? Is there a possibility to go to four dimension world like one of the three dimensional world? Lets find a solution to these questions !
John Cardy a theoretical physicist once in 1988 thought if there was a c-theorem in four dimensions. At the time, he reasonably expected his work on theories of quantum particles and fields to be professionally put to the test but it never happened. His far reaching principle to constrain all possible theories of quantum particles and fields he expected it to be quickly rebutted. But for almost 25 years that hasn’t happened — and it now seems that his theorem may have been quietly proved earlier this year.If the solution holds, it is likely to guide future attempts to explain physics beyond the current standard model. It will certainly have implications for any previously unknown particles that may be discovered at the Large Hadron Collider (LHC) at CERN, Europe’s particle physics lab near Geneva, Switzerland.Cardy's theory showed that, for d even, the one-point function of the trace of the stress tensor on the sphere, Sd, when suitably regularized, defines a c-function, which, at least to one loop order, is decreasing along RG trajectories and is stationary at RG fixed points, where it is proportional to the usual conformal anomaly.It also showed that the existence of such a c-function, if it satisfies these properties to all orders, is consistent with the expected behavior of QCD in four dimensions.
His conjecture is the a-theorem… a multitude of avenues in which quantum fields can be energetically excited (a) is always greater at high energies than at low energies. If this theory becomes correct, then it likely will explain physics beyond the current model and shed light on any possible unknown particles .According to theorists Zohar Komargodski and Adam Schwimmer of the Weizmann Institute of Science in Rehovot, Israel, the proof of Cardy’s theories was presented July 2011, and is slowly gaining notoriety among the scientific community as other theoretical physicists take note of his work.Many quantum field theories have yet to be exactly solved, meaning that they cannot be used to produce comprehensive predictions of what particles will do. One example is quantum chromodynamics — the theory of the strong nuclear force that describes the interactions between quarks and gluons. That lack leaves physicists struggling to relate physics at the high-energy, short-distance scale of quarks to the physics at longer-distance, lower-energy scales, such as that of protons and neutrons.Although lots of work has gone into relating short- and long-distance scales for particular quantum field theories, there are relatively few general principles that do this for all theories that can exist .But Cardy's a-theorem could be one such principle. A version of it had already been proven in two dimensions, but Cardy proposed that it might hold in four dimensions — such as the three dimensions of space and one of time that exist in the space in which we live. However, the theorem seemed to be have been killed off in 2008, when two physicists found a counter-example: a quantum field theory that didn’t obey the rule.Two years later Seiberg and his colleagues re-evaluated and discovered errors. These findings led to more studies of Cardy’'s work and allowed Schwimmer and Komargodski to state their conjecture.With Cardy'’s theory more thoroughly tested, chances are it will be applied more universally in the areas of quantum field theories. This may unify physics, including the area of supersymmetry and aid the findings with the LHC. The a-theorem “will be a guiding tool for theorists trying to understand the physics”.
Perhaps Cardy'’s work can also be included into condensed matter physics, an area where quantum field theories are used to elucidate on new states of materials. The only problem is the a-theorem has only had proof in two and four dimensions – where a few areas of condensed matter physics embrace layers containing just three dimensions – two in space and one in time.
“The physicists are just hoping that the theory comes true and gets a suitable proof and wont take another 20 year to do it.
[via:Physorg]
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