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We use the amplitude-based resummation of Feynman`s formulation of Einstein`s theory to arrive at a UV finite approach to quantum gravity. We show that we recover the UV fixed point recently claimed by the exact field-space renormalization group appr oach. We use our approach in the context of the attendant Planck scale cosmology formulation of Bonanno and Reuter to estimate the value of the cosmological constant as rho_Lambda=(0.0024 eV)^4. We show that the closeness of this estimate to experiment constrains susy GUT models.
We present a formulation of the operator product expansion that is infrared finite to all orders in the attendant massless non-Abelian gauge theory coupling constant, which we will often-times associate with the QCD theory, the theory that we actuall y have as our primary objective in view of the operation of the LHC at CERN. We make contact in this way with the recently introduced IR-improved DGLAP-CS theory and point-out phenomenological implications accordingly, with an eye toward the precision QCD theory for LHC physics.
We show that the more energetic superluminal neutrinos with quadratically dispersed superluminalities delta=beta^2-1, for beta=v/c where v is the neutrino velocity, also lose significant energy to radiation to the u+e^-+e^+ final state in travelling from CERN to Gran Sasso as has been shown to occur for those with constant superluminality by Cohen and Glashow if indeed delta simeq 5times 10^{-5}. In addition, we clarify the dependence of such radiative processes on the size of the superluminality.
We present the status and update of a new approach to quantum general relativity as formulated by Feynman from the Einstein-Hilbert action wherein amplitude-based resummation techniques are applied to the theorys loop corrections to yield results (su perficially) free of ultraviolet(UV) divergences. Recent applications are summarized.
It is shown that amplitude-based, exact resummation tames the un-cancelled IR divergences at O(alpha_s^2) in initial state radiation in QCD with massive quarks. Implications for precision predictions for LHC physics are discussed.
We show that, by using resummation techniques based on the extension of the methods of Yennie, Frautschi and Suura to Feynmans formulation of Einsteins theory, we get quantum field theoretic predictions for the UV fixed-point values of the dimensionl ess gravitational and cosmological constants. Connections to the phenomenological asymptotic safety analysis of Planck scale cosmology by Bonanno and Reuter are discussed.
It is shown that exact, amplitude-based resummation allows IR-improvement of the usual DGLAP theory. This results in a new set of kernels, parton distributions and attendant reduced cross sections, so that the QCD perturbative result for the respecti ve hadron-hadron or lepton-hadron cross section is unchanged order-by-order in $alpha_s$ at large squared-momentum transfers. We compare these new objects with their usual counter-parts and illustrate the effects of the IR-improvement in some phenomenological cases of interest with an eye toward precision applications in LHC physics scenarios.
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