The forum discussion centers around Sabine Hossenfelder's paper proposing a novel approach to resolving the tension between quantum gravity (QG) and quantum field theory (QFT). Hossenfelder suggests modifying the quantization condition to allow gravity to be perturbatively quantized at low energies while decoupling it from matter fields at energies above the Planck scale. The discussion highlights the implications of treating Planck's constant as a field that undergoes symmetry breaking, which could lead to testable predictions in physics. Participants express both enthusiasm and skepticism regarding the originality and practicality of Hossenfelder's approach.
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This suggests another argument against the hossi's proposal. If at high energies quantum fluctuations vanish, then the early inflationary phase of the Universe expansion cannot explain the primordial density fluctuations, which are needed to explain the observed inhomogenities in the spectrum of cosmic microwave background.Berlin said:If at high energies h --> 0 it would also mean that the big bang would consist of a near classical bose gas of spin-0 particles without Pauli exclusion.
Fermi-Dirac statistics in the limit h->0 is still a Fermi-Dirac statistics. This limit does not turn the anti-commutator into a commutator.Berlin said:But what would happen with the fermi statistics kicking in? Could we calculate the pressure of a developing fermi gas, maybe mimicking inflation?