A Beurling Theorem for Noncommutative Hardy Spaces Associated with a Semifinite von Neumann Algebra with Various Norms

We prove Beurling-type theorems for H-invariant spaces in relation to a semifinite von Neu-mann algebra M with a semifinite, faithful, normal tracial weight τ, using an extension of Arveson’s non-commutative Hardy space H-. First we prove a Beurling-Blecher-Labuschagne theorem for H-invariant subspaces of L p (M,τ) when 0 \u3c p ≤ -. We also prove a Beurling-Chen-Hadwin-Shen theorem for H -invariant subspaces of L a (M,τ) where a is a unitarily invariant, locally k 1 -dominating, mutually continuous norm with respect to &\tau;. For a crossed product of a von Neumann algebra M by an action β, M o β Z, we are able to completely characterize all H-invariant subspaces of L a (Mo β Z,t) using our results. As an example, we completely characterize all H-invariant subspaces of the Schatten p-class, S p (H) (0 \u3c p ≤ -), where H - is the lower tri-angular subalgebra of B(H). We also characterize the non-commutative Hardy space H -invariant subspaces in a Banach function space I(τ) on a semifinite von Neumann algebra M

Low Power Microwave Signal Detection With a Spin-Torque Nano-Oscillator in the Active Self-Oscillating Regime

A spin-torque nano-oscillator (STNO) driven by a ramped bias current can perform spectrum analysis quickly over a wide frequency bandwidth. The STNO spectrum analyzer operates by injection locking to external microwave signals and produces an output DC voltage $V_{\rm dc}$ that temporally encodes the input spectrum. We found, via numerical analysis with a macrospin approximation, that an STNO is able to scan a $10~\rm GHz$ bandwidth in less than $100~\rm ns$ (scanning rate $R$ exceeds $100~\rm MHz/ns$). In contrast to conventional quadratic microwave detectors, the output voltage of the STNO analyzer is proportional to the amplitude of the input microwave signal $I_{\rm rf}$ with sensitivity $S = dV_{\rm dc}/dI_{\rm rf} \approx 750~\rm mV/mA$. The minimum detectable signal of the analyzer depends on the scanning rate $R$ and, at low $R \approx 1~\rm MHz/ns$, is about $1~\rm pW$.Comment: 5 pages, 5 figure

Lust und Ekel: vom Reiz einer Grenzüberschreitung

"Zwar ist die unlustvolle Konnotation des Ekels schwer von der Hand zu weisen, weshalb er aus guten Gründen als potenziell vermeidenswerte Emotion gilt, doch lässt sich diese Zuschreibung keineswegs generalisieren. In bestimmten Kontexten liegen Lust und Ekel näher beieinander, als zunächst anzunehmen ist. Manch schauderhafte, obszöne, tabuisierte Darstellung – sei dies auf der Theaterbühne, in der Tageszeitung, auf dem TV- oder Computerbildschirm – löst Neugier und Schaulust bei ihren Rezipienten aus und erfreut sich einer gewissen Beliebtheit. Die lustvollen Dimensionen des Ekels sind auch und gerade im Bereich des Sexuellen nachzuweisen, wobei der Grat zwischen Erregungsmaximierung und Unlustgenerierung oft sehr schmal ist. Darum stößt die Artikulation von ekelkonnotierten Sexualinteressen nicht selten auf Schamschwellen – die aber beispielsweise innerhalb der SM-Prostitution herabgesetzt werden können." (Autorenreferat)"At first view disgust is primarily associated with reluctance and for this reason it is an undesirable emotion. But this cannot be generalized: In certain context, lust and disgust are closer together as maybe considered. Dreadful, obscene or perhaps tabooed images and expositions create curiosity. Particularly with regard to sexual dimensions, the negativism of disgust often turns into a positive and sensual emotion. But within this field, there is a fine line between increasing excitement and generating reluctance. Therefore, admitting to a disgusting sexual desire is tainted with shame. Nevertheless, it is entirely possible to reduce this sense of shame, for instance within SM prostitution." (author's abstract

Kritische Einblicke in die Altersforschung: Silke van Dyk über ein junges Forschungsfeld mit Zukunft

Silke van Dyk: Soziologie des Alters. Bielefeld: Transcript 2015. 978-3-8376-1632-

Tot sind immer nur die anderen: das eigene Lebensende zwischen Sterblichkeitswissen und Nicht-Erfahrbarkeit

"Der Tod gilt als eine anthropologische Konstante, der sich niemand entziehen kann. Trotz seiner Zurückdrängung durch Medikalisierung ist er als Zustand und Ereignis irreversibel. Er markiert eine Grenze, die einerseits Angst, andererseits Neugier auslösen kann. Subjekte haben ein Wissen davon, dass es diese Grenze gibt, dass also das eigene Leben ebenso wie das der anderen endlich ist. Wie es jedoch ist, tot zu sein, darüber fehlt sicheres Wissen. Das Wissen um den eigenen Tod generiert sich daher immer nur durch das Sterben der anderen. Der Beitrag diskutiert in erster Linie die Ambivalenz von Sterblichkeitswissen und Nichterfahrbarkeit unter besonderer Berücksichtigung der Frage, ob der Tod in der modernen Gesellschaft verdrängt wird - oder aufgrund seiner Geschwätzigkeit umso stärker präsent ist." (Autorenreferat

Noise properties of a resonance-type spin-torque microwave detector

We analyze performance of a resonance-type spin-torque microwave detector (STMD) in the presence of noise and reveal two distinct regimes of STMD operation. In the first (high-frequency) regime the minimum detectable microwave power $P_{\rm min}$ is limited by the low-frequency Johnson-Nyquist noise and the signal-to-noise ratio (SNR) of STMD is proportional to the input microwave power $P_{\rm RF}$. In the second (low-frequency) regime $P_{\rm min}$ is limited by the magnetic noise, and the SNR is proportional to $\sqrt{P_{\rm RF}}$. The developed formalism can be used for the optimization of the practical noise-handling parameters of a STMD.Comment: 3 pages, 2 figure

The principle of a virtual multi-channel lock-in amplifier and its application to magnetoelectric measurement system

This letter presents principles and applications of a virtual multi-channel lock-in amplifier that is a simple but effective method to recover small ac signal from noise with high presison. The fundamentals of this method are based on calculation of cross-correlation function. Via this method, we successfully built up a magnetoelectric measurement system which can perform precise and versatile measurements without any analog lock-in amplifier. Using the virtual multi-channel lock-in amplifier, the output of the magnetoelectric measurement system is extensively rich in magnetoelectric coupling behaviors, including coupling strength and phase lag, under various dc bias magnetic field and ac magnetic field.Comment: 11 pages, 6 figures. To be submitted to Rev. Sci. Instr

Autonomie der Trauer

Funeral culture is changing rapidly. In recent years, graveyards and burial rituals in Germany have altered significantly. They no longer reflect mechanisms of collective sense-making; instead, they represent individual lifeworlds. Death and the decisions and actions surrounding it have, in effect, become characterised by pluralism.When it comes to legal regulations, however, no change is visible. The law does not interpret the aforementioned cultural transformation from the perspective of the bereaved. It is thus not surprising that graveyard rules and especially the stipulation that human remains may only be interred in a cemetery have come under criticism.Yet today, practices have evolved by which the bereaved can sidestep the rules and keep the ashes of their deceased relatives with them, or scatter them at alternative locations. The trigger for this silent revolution is individualisation. However much individual decisions play a role in this respect, this development is also the result of changes within the cultural mind. They both mark a shift towards mourning becoming more autonomous