192,856 research outputs found
Pedersen ideals of tensor products of nonunital C*-algebras
No full textWe show that positive elements of a Pedersen ideal of a tensor product can be
approximated in a particularly strong sense by sums of tensor products of
positive elements. This has a range of applications to the structure of tracial
cones and related topics, such as the Cuntz-Pedersen space or the Cuntz
semigroup. For example, we determine the cone of lower semicontinuous traces of
a tensor product in terms of the traces of the tensor factors, in an arbitrary
C*-tensor norm. We show that the positive elements of a Pedersen ideal are
sometimes stable under Cuntz equivalence. We generalize a result of Pedersen's
by showing that certain classes of completely positive maps take a Pedersen
ideal into a Pedersen ideal. We provide theorems that in many cases compute the
Cuntz semigroup of a tensor product.Comment: circulated as preprint 2017
Pedersen, Christiern
No full textLeksikonartikel om humanisten, forfatteren Christiern Pedersen (c.1480-1554
Froelichia procera Pedersen
No full textFroelichia procera (Seub.) Pedersen in Darwiniana 14: 448. 1967. ÷ Froelichia lanata var. procera Seub. in Mart., Fl. Bras. 5(1): 167. 1875. = Froelichia lanata var. laciniata Suess. in Repert. Spec. Nov. Regni Veg. 39: 6. 1935, syn. nov. Holotypus: PARAGUAY. Guairá: “Ea. Primera ”, I.1932, Jörgensen, P. 4717 (MO [MO- 256764] [foto]!). Isotypi: (BR, C, S). F. lanata var. laciniata: Pedersen (1967: 449) incluye entre los especímenes determinados como F. procera a la colección Jörgensen 4717 sin darse cuenta que se trata del tipo de la var. laciniata . Formalizamos aquí la opinión taxonómica de Pedersen, con la publicación de este sinónimo nuevo.Published as part of Ramella, Lorenzo, 2016, Nomenclatura, tipificaciones y sinónimos nuevos en la familia Amaranthaceae de la Flora del Paraguay, pp. 311-326 in Candollea 71 (2) on page 316, DOI: 10.15553/c2016v712a16, http://zenodo.org/record/572180
Curve-fitting proposed theoretical results to the empirical data in Pedersen [27] (Figure 14), Pedersen [28] (Figure 5), Kloch [29] (Figure 6), and Pedersen [27] (Figure 10), shown in (a), (b), (c) and (d), respectively.
No full text<p>Curve-fitting proposed theoretical results to the empirical data in Pedersen [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132555#pone.0132555.ref027" target="_blank">27</a>] (Figure 14), Pedersen [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132555#pone.0132555.ref028" target="_blank">28</a>] (Figure 5), Kloch [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132555#pone.0132555.ref029" target="_blank">29</a>] (Figure 6), and Pedersen [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132555#pone.0132555.ref027" target="_blank">27</a>] (Figure 10), shown in (a), (b), (c) and (d), respectively.</p
Claus Bjørn, Grundtvig som politiker - Udgivet af Thorkild C.
No full textClaus Bjørn, Grundtvig as politician - published by Thorkild C. LybyReviewed by Vagn Wåhlin and Kim Arne Pedersen
Fig. 77. Cantharomyces spp. A–C. C. numidicus Maire. A, C. Mature thalli. B in Laboulbeniomycetes (Fungi, Ascomycota) of Denmark
No full textFig. 77. Cantharomyces spp. A–C. C. numidicus Maire. A, C. Mature thalli. B. Appendage basal cell in detail. – D–F. C. orientalis Speg. Mature thalli. – G. C. platystethi Thaxt. Mature thallus with labelled antheridium (an). Scale bars: 50 µm. Photographs from slides ZMUC C-F-122850 (A), ZMUC C-F-122935 (B–C), ZMUC C-F-122482 (D), ZMUC C-F-122831 (E), ZMUC C-F-123217 (F), ZMUC C-F-124182 (G).Published as part of Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, pp. 1-425 in European Journal of Taxonomy 781 on page 318, DOI: 10.5852/ejt.2021.781.1583, http://zenodo.org/record/582892
The Pedersen Rigidity Problem
No full textIf is an action of a locally compact abelian group G on a C*-algebra A, Takesaki-Takai duality recovers (A, α) up to Morita equivalence from the dual action of Ĝ on the crossed product A × α G. Given a bit more information, Landstad duality recovers (A, α) up to isomorphism. In between these, by modifying a theorem of Pedersen, (A, α) is recovered up to outer conjugacy from the dual action and the position of A in M(A ×α G). Our search (still unsuccessful, somehow irritating) for examples showing the necessity of this latter condition has led us to formulate the "Pedersen Rigidity problem". We present numerous situations where the condition is redundant, including G discrete or A stable or commutative. The most interesting of these "no-go theorems" is for locally unitary actions on continuous-trace algebras.Si α es una acción de un grupo abeliano localmente compacto G sobre una C*-álgebra A, la dualidad de Takesaki-Takai recupera (A, α), salvo equivalencia de Morita, de la acción dual de Ĝ sobre el producto cruzado A × α G. Mediante un poco más de información, la dualidad de Landstad recupera (A, α) salvo isomorfismo. De manera intermedia, mediante la modificación de un teorema de Pedersen, (A α) es recuperado, salvo conjugación externa, de la acción dual y de la posición de A en M(A ×α G). Nuestra búsqueda (todavía sin éxito, de alguna manera irritante) de ejemplos que prueben la necesidad de esta última condición, nos ha conducido a a formular el "problema de rigidez de Pedersen". Presentamos numerosas situaciones donde la condición es redundante, incluídos los casos en que G es discreto, o bien A es estable o conmutativo. Lo más interesante de estos "teoremas de no usar" es para acciones localmente unitarias sobre álgebras trazo-continuas
Staging negotiation spaces as a means for co-designing an insulin service system in India
No full textThis chapter seeks to investigate potential navigational moves of designers through a specific case study of making insulin available to people at the BoP in India and views staging as a central aspect in negotiating concerns in collaborative design projects in general. Staging is the act of building network relations by orchestrating spaces for negotiation (Pedersen 2020) and refers to a process of (a) framing an envisaged performance in a scenic space based on an interpretation of the initial ‘design brief’ of a project; and (b) producing props that inscribe this framing into potential intermediary objects that mediates between actors and allow for discussions and negotiations of controversies. Further navigational moves include (c) circulating these objects amongst diverse actors to facilitate negotiations; and (d) reframing the design brief to stage yet another performance with new actors and props
A characterization of the Pedersen ideal of 𝐶𝐷0(𝑇,𝐵₀(𝐻)) and a counter-example
No full textLet T be a locally compact Hausdorff space, H a complex Hilbert space, and A the
C
∗
{C^\ast }
-algebra
C
0
(
T
,
B
0
(
H
)
)
{C_0}(T,{B_0}(H))
. Let
A
0
{A_0}
be the Pedersen ideal of A and
J
A
{J_A}
the two-sided ideal of A consisting of all x having compact support, for which
sup
{
dim
x
(
t
)
:
t
∈
T
}
>
∞
\sup \{ \dim x(t):t \in T\} > \infty
. It is known that
A
0
⊆
J
A
{A_0} \subseteq {J_A}
, and equality has been conjectured by Pedersen. We give a new characterization of
A
0
{A_0}
which enables us to show that the conjecture is false.</p
How well can we estimate Pedersen conductance from the THEMIS white-light all-sky cameras?
No full textWe show that a THEMIS (Time History of Events and Macroscale Interactions during Substorms) white‐light all‐sky imager (ASI) can estimate Pedersen conductance with an uncertainty of 3 mho or 40%. Using a series of case studies over a wide range of geomagnetic activity, we compare estimates of Pedersen conductance from the backscatter spectrum of the Poker Flat Advanced Modular Incoherent Scatter Radar (ISR) with auroral intensities. We limit this comparison to an area bounding the radar measurements and within a limited area close to, (but off) imager zenith. We confirm a linear relationship between conductance and the square root of auroral intensity predicted from a simple theoretical approximation. Hence we extend a previous empirical result found for green‐line emissions to the case of white‐light off‐zenith emissions. The difference between the radar conductance and the best‐fit relationship has a mean of ‐0.76 ± 4.8 mho, and a relative mean difference of 21% ± 78%. The uncertainties are reduced to ‐0.72 ± 3.3 mho and 0% ± 40% by averaging conductance over 10 minutes, which we attribute to the time that auroral features take to move across the imager field being greater than the 1 minute resolution of the radar data. Our results demonstrate and calibrate the use of THEMIS ASIs for estimating Pedersen conductance. This technique allows the extension of estimates of Pedersen conductance from ISRs to derive continental‐scale estimates on scales of ~1‐10 minutes and ~100 km2. It thus complements estimates from low‐altitude satellites, satellite auroral imagers, and ground‐based magnetometers
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