63,370 research outputs found
Crying for Repression: Populist and Democratic Biopolitics in Times of COVID-19
We live in very Foucauldian times, as the many think-pieces published on biopolitics and COVID-19 show. Yet what is remarkable—biopolitically—about the current situation has gone largely unnoticed: We are witnessing a new form of biopolitics today that could be termed populist biopolitics. Awareness of this populist biopolitics helps illuminate what is needed today: democratic biopolitics
The Lyddane-Sachs-Teller relationship for polar vibrations in materials with monoclinic and triclinic crystal systems
A generalization of the Lyddane-Sachs-Teller relation is presented for polar
vibrations in materials with monoclinic and triclinic crystal systems. The
generalization is derived from an eigen displacement vector summation approach,
which is equivalent to the microscopic Born-Huang description of polar lattice
vibrations. An expression for a general oscillator strength is also described
for materials with monoclinic and triclinic crystal systems. A generalized
factorized dielectric response function characteristic for monoclinic and
triclinic materials is proposed. The generalized Lyddane-Sachs-Teller relation
is found valid for monoclinic -GaO, where accurate experimental
data became available recently from a comprehensive generalized ellipsometry
investigation. Data for triclinic crystal systems can be measured by
generalized ellipsometry as well, and are anticipated to become available soon
and results can be compared with the generalized relations presented hereComment: 5 pages, 1 figur
Specifying nonspecific evidence
In an earlier article [J. Schubert, On nonspecific evidence, Int. J. Intell.
Syst. 8(6), 711-725 (1993)] we established within Dempster-Shafer theory a
criterion function called the metaconflict function. With this criterion we can
partition into subsets a set of several pieces of evidence with propositions
that are weakly specified in the sense that it may be uncertain to which event
a proposition is referring. Each subset in the partitioning is representing a
separate event. The metaconflict function was derived as the plausibility that
the partitioning is correct when viewing the conflict in Dempster's rule within
each subset as a newly constructed piece of metalevel evidence with a
proposition giving support against the entire partitioning. In this article we
extend the results of the previous article. We will not only find the most
plausible subset for each piece of evidence as was done in the earlier article.
In addition we will specify each piece of nonspecific evidence, in the sense
that we find to which events the proposition might be referring, by finding the
plausibility for every subset that this piece of evidence belong to the subset.
In doing this we will automatically receive indication that some evidence might
be false. We will then develop a new methodology to exploit these newly
specified pieces of evidence in a subsequent reasoning process. This will
include methods to discount evidence based on their degree of falsity and on
their degree of credibility due to a partial specification of affiliation, as
well as a refined method to infer the event of each subset.Comment: 39 pages, 2 figure
QED in the worldline representation
Simultaneously with inventing the modern relativistic formalism of quantum
electrodynamics, Feynman presented also a first-quantized representation of QED
in terms of worldline path integrals. Although this alternative formulation has
been studied over the years by many authors, only during the last fifteen years
it has acquired some popularity as a computational tool. I will shortly review
here three very different techniques which have been developed during the last
few years for the evaluation of worldline path integrals, namely (i) the
``string-inspired formalism'', based on the use of worldline Green functions,
(ii) the numerical ``worldline Monte Carlo formalism'', and (iii) the
semiclassical ``worldline instanton'' approach.Comment: 18 pages, 7 figures, talk given at VI Latinamerican Symposium on High
Energy Physics, Nov. 1-8, 2006, Puerto Vallarta, Mexico; references added and
corrected (no other changes
The Structure of the Bern-Kosower Integrand for the N-Gluon Amplitude
An ambiguity inherent in the partial integration procedure leading to the
Bern-Kosower rules is fixed in a way which preserves the complete permutation
symmetry in the scattering states. This leads to a canonical version of the
Bern-Kosower representation for the one-loop N - photon/gluon amplitudes, and
to a natural decomposition of those amplitudes into permutation symmetric gauge
invariant partial amplitudes. This decomposition exhibits a simple recursive
structure.Comment: 12 pages, no figures, latex, uses dina4.st
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