3,375 research outputs found
Business-friendly contracting : how simplification and visualization can help bring it to practice
One thesis of this book is that the legal function within businesses will shift from a paradigm of security to one of opportunity. This chapter embraces that likelihood in the context of business contracting, where voices calling for a major shift are starting to surface. It explores how contracts can be used to reach better outcomes and relationships, not just safer ones. It introduces the concept of business-friendly contracting, highlighting the need for contracts to be seen as business tools rather than exclusively as legal tools, and working as business enablers rather than obstacles. By changing the design of contracts and the ways in which those contracts are communicated—through simplification and visualization, for example—legal and business operations can be better integrated. Contracts can then be more useful to business, and contract provisions can actually become more secure by becoming easier to negotiate and implement.fi=vertaisarvioitu|en=peerReviewed
Vacuum fluctuation force on a rigid Casimir cavity in a gravitational field
We discuss the possibility of verifying the equivalence principle for the
zero-point energy of quantum electrodynamics, by evaluating the force, produced
by vacuum fluctuations, acting on a rigid Casimir cavity in a weak
gravitational field. The resulting force has opposite direction with respect to
the gravitational acceleration; the order of magnitude for a multi-layer cavity
configuration is derived and experimental feasibility is discussed, taking into
account current technological resources.Comment: 13 pages, Latex. In the revised version, the presentation has been
improve
Vacuum Polarization and Energy Conditions at a Planar Frequency Dependent Dielectric to Vacuum Interface
The form of the vacuum stress-tensor for the quantized scalar field at a
dielectric to vacuum interface is studied. The dielectric is modeled to have an
index of refraction that varies with frequency. We find that the stress-tensor
components, derived from the mode function expansion of the Wightman function,
are naturally regularized by the reflection and transmission coefficients of
the mode at the boundary. Additionally, the divergence of the vacuum energy
associated with a perfectly reflecting mirror is found to disappear for the
dielectric mirror at the expense of introducing a new energy density near the
surface which has the opposite sign. Thus the weak energy condition is always
violated in some region of the spacetime. For the dielectric mirror, the mean
vacuum energy density per unit plate area in a constant time hypersurface is
always found to be positive (or zero) and the averaged weak energy condition is
proven to hold for all observers with non-zero velocity along the normal
direction to the boundary. Both results are found to be generic features of the
vacuum stress-tensor and not necessarily dependent of the frequency dependence
of the dielectric.Comment: 16 pages, 4 figures, Revtex style Minor typographic corrections to
equations and tex
Light propagation in non-trivial QED vacua
Within the framework of effective action QED, we derive the light cone
condition for homogeneous non-trivial QED vacua in the geometric optics
approximation. Our result generalizes the ``unified formula'' suggested by
Latorre, Pascual and Tarrach and allows for the calculation of velocity shifts
and refractive indices for soft photons travelling through these vacua.
Furthermore, we clarify the connection between the light velocity shift and the
scale anomaly. This study motivates the introduction of a so-called effective
action charge that characterizes the velocity modifying properties of the
vacuum. Several applications are given concerning vacuum modifications caused
by, e.g., strong fields, Casimir systems and high temperature.Comment: 13 pages, REVTeX, 3 figures, to appear in Phys. Rev.
The Energy Density in the Casimir Effect
We compute the expectations of the squares of the electric and magnetic
fields in the vacuum region outside a half-space filled with a uniform
dispersive dielectric. We find a positive energy density of the electromagnetic
field which diverges at the interface despite the inclusion of dispersion in
the calculation. We also investigate the mean squared fields and the energy
density in the vacuum region between two parallel half-spaces. Of particular
interest is the sign of the energy density. We find that the energy density is
described by two terms: a negative position independent (Casimir) term, and a
positive position dependent term with a minimum value at the center of the
vacuum region. We argue that in some cases, including physically realizable
ones, the negative term can dominate in a given region between the two
half-spaces, so the overall energy density can be negative in this region.Comment: 16 pages, 4 figures; 3 references and some new material in Sect. 4.4
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