14,869 research outputs found
Casimir Effect and Global Theory of Boundary Conditions
The consistency of quantum field theories defined on domains with external
borders imposes very restrictive constraints on the type of boundary conditions
that the fields can satisfy. We analyse the global geometrical and topological
properties of the space of all possible boundary conditions for scalar quantum
field theories. The variation of the Casimir energy under the change of
boundary conditions reveals the existence of singularities generically
associated to boundary conditions which either involve topology changes of the
underlying physical space or edge states with unbounded below classical energy.
The effect can be understood in terms of a new type of Maslov index associated
to the non-trivial topology of the space of boundary conditions. We also
analyze the global aspects of the renormalization group flow, T-duality and the
conformal invariance of the corresponding fixed points.Comment: 11 page
Development of polymer network of phenolic and epoxies resins mixed with linseed oil: pilot study
Epoxy resin was mixed with phenolic resins in different percentages by weight. Composite 40/60 means the proportion by weight of epoxy resin is 40 percent. It was found that only composites 50/50 and 40/60 could be cured in ambient conditions. Dynamic mechanical analysis showed that only these two composites form interpenetrating polymer network. The addition of linseed oil to the two resins results also in the formation of interpenetrating network irrespective of proportion by weight of the resins; the mechanical properties will only be better when the percentage by weight of epoxy resin is higher; the aim of reducing cost and at the same time maintaining the mechanical properties cannot be fully achieved because epoxy resin is much more expensive than its counterpart
Calculable inverse-seesaw neutrino masses in supersymmetry
We provide a scenario where naturally small and calculable neutrino masses
arise from a supersymmetry breaking renormalization-group-induced vacuum
expectation value. We adopt a minimal supergravity scenario without ad hoc
supersymmetric mass parameters. The lightest supersymmetric particle can be an
isosinglet scalar neutrino state, potentially viable as WIMP dark matter
through its Higgs new boson coupling. The scenario leads to a plethora of new
phenomenological implications at accelerators including the Large Hadron
Collider.Comment: LaTeX, 5 pages, 4 figures. Comments and references added. Final
version to appear in PR
- …