2,181 research outputs found
Inertial Spontaneous Symmetry Breaking and Quantum Scale Invariance
Weyl invariant theories of scalars and gravity can generate all mass scales
spontaneously, initiated by a dynamical process of "inertial spontaneous
symmetry breaking" that does not involve a potential. This is dictated by the
structure of the Weyl current, , and a cosmological phase during which
the universe expands and the Einstein-Hilbert effective action is formed.
Maintaining exact Weyl invariance in the renormalised quantum theory is
straightforward when renormalisation conditions are referred back to the VEV's
of fields in the action of the theory, which implies a conserved Weyl current.
We do not require scale invariant regulators. We illustrate the computation of
a Weyl invariant Coleman-Weinberg potential
Inflation in a scale invariant universe
A scale-invariant universe can have a period of accelerated expansion at
early times: inflation. We use a frame-invariant approach to calculate
inflationary observables in a scale invariant theory of gravity involving two
scalar fields - the spectral indices, the tensor to scalar ratio, the level of
isocurvature modes and non-Gaussianity. We show that scale symmetry leads to an
exact cancellation of isocurvature modes and that, in the scale-symmetry broken
phase, this theory is well described by a single scalar field theory. We find
the predictions of this theory strongly compatible with current observations.Comment: 9 pages, 2 figures; v2: minor clarifications added, matches published
versio
Encapsulation of a {Cu16} cluster containing four [Cu4O4] cubanes within an isopolyoxometalate {W44} cluster
We report a {Cu16} embedded within a {W44} cluster containing four cubane-like [Cu4O4] units within an isopolyoxotungstate (isoPOT) in a {Na4Cu4[(H2W11O38) (CH3COO)(OH)3]}4·88H2O (1) and a polyanion Cu-linked {W11} chain Na6Cu2[(H2W11O38)(CH3COO)(OH)]·26H2O (2). Electronically, the redox properties show that both compounds 1 and 2 undergo irreversible reductions resulting in the demetalation of the compounds, whilst the magnetic behavior of 1 and 2 shows a weak antiferromagnetic and a stronger ferromagnetic coupling, respectively
Overview of the hypnodensity approach to scoring sleep for polysomnography and home sleep testing
- …