Parametric resonance of a two-dimensional electron gas under bichromatic irradiation

In an ultrahigh mobility 2D electron gas, even a weak nonparabolicity of the electron dispersion, by violating Kohn's theorem, can have a drastic effect on dc magnetotransport under ac drive. We study theoretically the manifestation of this effect in the dc response to the combined action of two driving ac-fields (bichromatic irradiation). Compared to the case of monochromatic irradiation, which is currently intensively studied both experimentally and theoretically, the presence of a second microwave source provides additional insight into the properties of an ac-driven 2D electron gas. In particular, we find that nonparabolicity, being the simplest cause for a violation of Kohn's theorem, gives rise to new qualitative effects specific to bichromatic irradiation. Namely, when the frequencies $\omega_1$ and $\omega_2$ are well away from the cyclotron frequency, $\omega_c$, our simple classical considerations demonstrate that the system becomes parametrically unstable with respect to fluctuations with frequency $(\omega_1+\omega_2)/2$. As an additional effect of nonparabolicity, this parametric instability can manifest itself in the dc properties of the system. This happens when $\omega_1$, $\omega_2$ and $\omega_c$ are related as 3:1:2, respectively. Even for weak detuning between $\omega_1$ and $\omega_2$, the effect of the bichromatic irradiation on the dc response in the presence of nonparabolicity can differ dramatically from the monochromatic case. In particular, the equations of motion can acquire multistable solutions. As a result, the diagonal dc-conductivity can assume several stable negative values at the same magnetic field.Comment: 11 pages, 10 figure

Foi et morale à l’âge de la contingence

Cet article aborde de manière critique un aspect important de la sociologie des religions de Peter Berger, notamment son hypothèse que le pluralisme moderne affaiblirait la religion. Cette hypothèse est abordée sur les plans historique, sociologique et psychologique. Je soutiens que Berger exagère l’homogénéité religieuse du passé, néglige les effets revitalisants du pluralisme religieux et déforme l’émergence de l’engagement religieux en lui appliquant la notion de choix. Cet article se conclut par des réflexions sur les possibilités qui s’offrent à une foi religieuse adaptée aux conditions du pluralisme moderne et d’une contingence croissante.This paper is a critical discussion of an important point in Peter Berger’s sociology of religion, namely his assumption that modern pluralism weakens religion. This thesis is discussed on a historical, sociological and psychological level. I argue that Berger exaggerates the religious homogeneity of the past, neglects the revitalizing effects religious pluralism can have, and distorts the emergence of religious commitment by applying the notion of choice to it. The paper ends with some reflections on the possibilities for a religious faith that is adapted to the conditions of modern pluralism and increasing contingency.Este artículo aborda de manera crítica un aspecto importante de la sociología de las religiones de Peter Berger, en particular, su hipótesis que el pluralismo moderno debilitaría la religión. Esta hipótesis se aborda a nivel histórico, sociológico y psicológico. Mantengo que Peter exagera la homogeneidad religiosa del pasado, descuida los efectos revitalizantes del pluralismo religioso y deforma la aparición del compromiso religioso aplicándole el concepto de elección. Este artículo se concluye con reflexiones sobre las posibilidades que se ofrecen a una fe religiosa adaptada a las condiciones del pluralismo moderno y de una contingencia creciente

Communitarianism: A German Perspective

This lecture was given in Bloomington for the Indiana University Institute and Society for Advanced Study on September 23, 1994

Are secondary markets beneficial for a virtual world operator?

Selling virtual goods for real money has become the dominant business model for virtual worlds in the past decade. As the amount of money involved in virtual goods sales increases, market performance questions gain relevance. In this thesis, we examine the effects of secondary markets on the profitability of a virtual world service provider operating under a virtual goods sales model. More specifically, we ask whether the service provider should tolerate secondary markets or seek to kill them off. The structure of this thesis is as follows: we first review how virtual worlds operate as businesses and provide an analysis of the market conditions faced by a virtual world operator to provide sufficient context for the reader. We then examine the inner workings of virtual economies and review structures commonly encountered within them. Next, we conduct a literature review on real world secondary market models and analyses. Finally, we evaluate the implications of real world secondary market results on secondary markets for virtual goods. In the final section, we present conclusions and possible avenues for further study. We find that recent durable goods research suggests that a profit-maximizing monopolist will not shut down secondary markets, but will choose to reduce durability of goods instead and that these results can apply to virtual worlds as well. However, we also show that the question of allowing or not allowing secondary markets cannot be answered based on profitability alone and that service providers have to also account for externalities brought on by secondary markets

Punishment and Respect: The Sacralization of the Person and its Endangerment. Translated by Simon Susen

Discussions of punishmentin the modern era turn on the question of the definition and importance of human rights. To understand this linkage, it is important to examine critically two narratives of the origin and development of modern Western forms of punishment, namely that of the Enlightenment, and that of the process of ‘disciplination’ to be found in the work of Foucault. In this article, I suggest an alternative to both these narratives, namely a Durkheimian attention to the process of the ‘sacralization of the person’ which indicates the importance ofreading thedevelopment ofmodernpunishment aspart of a larger process of ‘inclusion’ in which more and more people were included within the category of human personhood. A focus on the sacrality of the person as central to the notion of punishment also helps us to understand the ambiguity of punishment in the modern era, as well as threats posed to human rights by certain contemporary punishment regimes

Value generalization: limitations and possibilities of a communication about values

"Dieser Beitrag stellt einen Versuch dar, die Bedeutung des Begriffs 'Wertegeneralisierung' für die Moralphilosophie und somit hoffentlich auch für die Wirtschafts- und Unternehmensethik darzustellen. Die Bedeutung dieses Begriffs liegt in seinem Beitrag zu dem, was man die Logik einer Kommunikation über Werte nennen könnte. Diese Logik ist vom rational-argumentativen Diskurs zu unterscheiden, aber auch von der Vorstellung einer unversöhnlichen Konfrontation der Werte, Identitäten oder Kulturen oder jeder anderen Form eines irrationalistischen Dezisionismus, der vorgibt, man könne letzte Werte nur in existentieller Weise wählen ohne jede Begründung oder intersubjektive Plausibilität." (Autorenreferat)"This contribution is an attempt to demonstrate that the concept of 'value generalization' is of considerable importance for moral philosophy and therefore hopefully also for those interested in business and economic ethics. The importance of this concept lies in its relevance for what one could call 'the logic of a communication about values'. This logic is different from the structure of rational-argumentative discourse in a strict sense, but also far from a mere clash of values or identities or civilizations or any form of irrationalist decisionism as if ultimate values could only be chosen in an existential way without any reasoning and intersubjective plausibility." (author's abstract

On be...ing political: Empat model identitas ramah-gereja di bawah bayang-bayang kanopi suci kebangsaan

This article discusses the idea of a hospitable church that struggles under the sacred canopy of the state, especially in the Indonesian context. By using Stanley Hauerwas’ social ethics and ecclesiology that views the church as an exemplary community, this article proposes an ecclesial model that maintains the tension of being true to its nature on the one hand and being political on the other hand. Such a model is demonstrated through its four dimensions: beholding, becoming, belonging, and befriending. The paper ends with a conclusion, in which the author reflects on the four dimensions by using the perspective of the four classical marks of the church (notae ecclesiae). AbstrakArtikel ini membahas gagasan mengenai gereja dengan identitas-ramah yang berjuang di bawah kanopi suci negara, khususnya dalam konteks Indonesia. Dengan menggunakan etika sosial dan eklesiologi Stanley Hauerwas, yang memandang gereja sebagai komunitas eksemplaris, artikel ini mengusul-kan model gerejawi yang mempertahankan ketegangan antara menjadi setia pada hakikatnya di satu sisi dan menjadi politis di sisi lain. Model semacam itu ditunjukkan melalui empat dimensinya: beholding, becoming, belonging, dan befriending. Makalah diakhiri dengan kesimpulan yang di dalamnya penulis merefleksikan empat dimensi di atas dengan menggunakan perspektif empat tanda klasik gereja (notae ecclesiae)

Deployment Separation Impact on Military Spouse Well-Being

Military spouses are confronted with multiple responsibilities daily. These demands intensify when their spouses deploy. By extension, military families respond differently and adapt to these stressors differently than civilian families. This necessitates coping with dynamic changes described as adequate or maladaptive. The deployment of one\u27s spouse is also affiliated with mixed feelings such as anger, fear, joy, loneliness, anticipation, and relief. While the active-duty spouse is deployed, communication with the family allows a more significant emotional balance for the military member, the spouse, and the children to obtain a more favorable performance in their functions. Without proper and consistent communication, which often occurs during deployment, the emotional well-being of the spouses left behind is affected. Throughout the life cycle of military families, they suffer and must deal with internal pressures that result from changes inherent to the development of individuals and subsystems and external forces that require their adaptation to the social institutions that influence them. This is because both the military and the family systems are social institutions that require commitment, loyalty, time, and energy from their constituent members. The long-term deployment of military members results in spouses\u27 emotional distress and psychological issues. They face stress, depression, and financial issues