5,769 research outputs found
Scientia temporum & rerum : History or Antiquarianism? The collection of examples in Georg Calixtus' De studio historiarum oratio (1629)
This paper explores an early modern application of the Stoic principle of similitudo temporum to the study of history. In so doing, it highlights the tension between historiography and antiquarianism, suggesting that the collection of remains – whether material or immaterial – was understood in at least some early modern circles as an integral part of the historiographic process. It also emphasises the evolving meaning of “history” during this time, drawing attention to the perceived novelty of such antiquarian approaches to the study of the past, and briefly exploring subtle differences between the example at hand and the work and activities of better-known figures such as Nicolas-Claude Fabri de Peiresc and Justus Lipsius. As such, this paper makes a contribution to our evolving understanding of early modern scholarship, and draws attention to the variegated approaches of its practitioners to contemporary issues
The Noncommutative Standard Model and Polarization in Charged Gauge Boson Production at the LHC
We study the pair production of charged gauge bosons at the LHC in a
noncommutative extension of the standard model. We use angular distributions in
the decays of the gauge bosons to partially reconstruct polarized cross
sections. We use this, together with CP considerations, to construct more
sensitive observables that allow to separate space-time from space-space
noncommutativities.Comment: 13 pages, 8 figures; minor cosmetic change; clarifying remarks on our
Feynman rules, add explicit calculation of Ward identities to appendi
Changing Effects of Monetary Policy in the U.S. –Evidence from a Time-Varying Coefficient VAR
We estimate a time-varying coefficient VAR model for the U.S. economy to analyse (i) if the effect of monetary policy on output has been changing systematically over time, and (ii) if monetary policy has asymmetric effects over the business cycle. We find that the impact of monetary policy shocks has been gradually declining over the sample period (1962-2002), as some theories of the monetary transmission mechanism imply. In addition, our results indicate that the effects of monetary policy are greater in a recession than in a boom.
A Semidefinite Hierarchy for Containment of Spectrahedra
A spectrahedron is the positivity region of a linear matrix pencil and thus
the feasible set of a semidefinite program. We propose and study a hierarchy of
sufficient semidefinite conditions to certify the containment of a
spectrahedron in another one. This approach comes from applying a moment
relaxation to a suitable polynomial optimization formulation. The hierarchical
criterion is stronger than a solitary semidefinite criterion discussed earlier
by Helton, Klep, and McCullough as well as by the authors. Moreover, several
exactness results for the solitary criterion can be brought forward to the
hierarchical approach. The hierarchy also applies to the (equivalent) question
of checking whether a map between matrix (sub-)spaces is positive. In this
context, the solitary criterion checks whether the map is completely positive,
and thus our results provide a hierarchy between positivity and complete
positivity.Comment: 24 pages, 2 figures; minor corrections; to appear in SIAM J. Opti
NoSEBrEaK - Attacking Honeynets
It is usually assumed that Honeynets are hard to detect and that attempts to
detect or disable them can be unconditionally monitored. We scrutinize this
assumption and demonstrate a method how a host in a honeynet can be completely
controlled by an attacker without any substantial logging taking place
Changing Effects Of Monetary Policy In The US - Evidence From A Time-Varying Coefficients VAR
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