Fermi and the Theory of Weak Interactions
... One can split up the above diagram into two parts, one describing the emission of the photon by the proton and the other describing the absorption of the photon by the electron. So the basic QED interaction in symbolic form is written as eJE A. Here A denotes the quantum ¯eld operator for the photon ...
... One can split up the above diagram into two parts, one describing the emission of the photon by the proton and the other describing the absorption of the photon by the electron. So the basic QED interaction in symbolic form is written as eJE A. Here A denotes the quantum ¯eld operator for the photon ...
Enhanced Symmetries and the Ground State of String Theory
... One of the great puzzles of string theory is: why are the gauge couplings we observe small and unified, if the underlying theory is strongly coupled. The weakly coupled heterotic string provides a simple picture of coupling unification, but it is not clear why this should hold at stronger coupling, ...
... One of the great puzzles of string theory is: why are the gauge couplings we observe small and unified, if the underlying theory is strongly coupled. The weakly coupled heterotic string provides a simple picture of coupling unification, but it is not clear why this should hold at stronger coupling, ...
Fermion Doubling in Loop Quantum Gravity - UWSpace
... theory where the NN theorem may be applied. Item 2 grants us a graph to work on. We use the Born-Oppenheimer approximation [4] to concentrate on the fermion degrees of freedom and expand around the gravitational pieces, we need the fermions to live on a background graph Γ to investigate doubling. No ...
... theory where the NN theorem may be applied. Item 2 grants us a graph to work on. We use the Born-Oppenheimer approximation [4] to concentrate on the fermion degrees of freedom and expand around the gravitational pieces, we need the fermions to live on a background graph Γ to investigate doubling. No ...
Discrete quantum gravity: a mechanism for selecting the value of
... Fundamental constants in nature need to fall within a rather narrow set of values for the universe to have its current form, in particular to accommodate life. When written in dimensionless form, unnaturally large ratios appear between various of the fundamental constants. Inflation has been propose ...
... Fundamental constants in nature need to fall within a rather narrow set of values for the universe to have its current form, in particular to accommodate life. When written in dimensionless form, unnaturally large ratios appear between various of the fundamental constants. Inflation has been propose ...
WHY GROUPS? Group theory is the study of symmetry. When an
... can help us study it. We apply the label “symmetric” to anything that stays invariant under some transformations. This could apply to geometric figures (a circle is highly symmetric, being invariant under any rotation), but also to more abstract objects like functions: x2 + y 2 + z 2 is invariant un ...
... can help us study it. We apply the label “symmetric” to anything that stays invariant under some transformations. This could apply to geometric figures (a circle is highly symmetric, being invariant under any rotation), but also to more abstract objects like functions: x2 + y 2 + z 2 is invariant un ...
Structures and Categories
... generalization was introduced, that of gaugenatural bundles that the relevance of this functorial approach to physical applications began to be clearly perceived. Indeed, every classical field theory can be regarded as taking place on some jet prolongation of some gaugenatural (vector or affine) bun ...
... generalization was introduced, that of gaugenatural bundles that the relevance of this functorial approach to physical applications began to be clearly perceived. Indeed, every classical field theory can be regarded as taking place on some jet prolongation of some gaugenatural (vector or affine) bun ...
String theory as a Lilliputian world
... a renormalizing of the bare coupling constant (K0 = 1/(2πα′0 )) to define a two-point function with a positive, finite mass. In the limit where the cutoff a → 0 the Hausdorff dimension of the ensemble of quantum surfaces is dH = 4, but then the effective string tension defined as in eq. (28) will be ...
... a renormalizing of the bare coupling constant (K0 = 1/(2πα′0 )) to define a two-point function with a positive, finite mass. In the limit where the cutoff a → 0 the Hausdorff dimension of the ensemble of quantum surfaces is dH = 4, but then the effective string tension defined as in eq. (28) will be ...
LHCtalkS08
... More Variations on A Theme One can scatter a gluon off of a heavy quark in the proton as well as a light quark – This quark can be identified as a bottom or charmed quark by “tagging” the jet – This measures how much b (or c) is in the proton • Determines backgrounds to various searches, like Hig ...
... More Variations on A Theme One can scatter a gluon off of a heavy quark in the proton as well as a light quark – This quark can be identified as a bottom or charmed quark by “tagging” the jet – This measures how much b (or c) is in the proton • Determines backgrounds to various searches, like Hig ...
Slide - University of Maryland
... If you take the near-zone limit of the P-gauge metric perturbation, then the nearzone metric is just the ordinary Schwarzschild metric in isotropic coordinates. So, we say that the perturbed position of the particle vanishes in P gauge. But we worked in P-smooth gauges. What is the description there ...
... If you take the near-zone limit of the P-gauge metric perturbation, then the nearzone metric is just the ordinary Schwarzschild metric in isotropic coordinates. So, we say that the perturbed position of the particle vanishes in P gauge. But we worked in P-smooth gauges. What is the description there ...
Renormalization
... One might be tempted to conclude from this that a phenomenological description is simply not possible beyond the delta function approximation. After all, if the underlying theory is known, one can always compute the corrections without any approximation, and it might be argued that the inconsistenci ...
... One might be tempted to conclude from this that a phenomenological description is simply not possible beyond the delta function approximation. After all, if the underlying theory is known, one can always compute the corrections without any approximation, and it might be argued that the inconsistenci ...
Get cached
... product of three factors of the type given by formula (10) and discussed in section 3. It follows from that discussion that the whole reflected energy will be thrown into the same eight directions which were found on the basis of the quantum theory. This proves in a general way the complete identity ...
... product of three factors of the type given by formula (10) and discussed in section 3. It follows from that discussion that the whole reflected energy will be thrown into the same eight directions which were found on the basis of the quantum theory. This proves in a general way the complete identity ...
arXiv:1203.2158v1 [hep-th] 9 Mar 2012 The “tetrad only” theory
... functional flow equations, the “hybrid calculations” proposed in the literature (using the tetrad for fermionic diagrams only, and the metric in all others) are unlikely to be quantitatively reliable. Moreover we find that, unlike in perturbation theory, the non-propagating Faddeev-Popov ghosts rela ...
... functional flow equations, the “hybrid calculations” proposed in the literature (using the tetrad for fermionic diagrams only, and the metric in all others) are unlikely to be quantitatively reliable. Moreover we find that, unlike in perturbation theory, the non-propagating Faddeev-Popov ghosts rela ...