The Bousso entropy bound in selfgravitating gas of massless particles

The Bousso entropy bound is investigated in a static spherically symmetric spacetime filled with an ideal gas of massless bosons or fermions. Especially lightsheets generated by spheres are considered. Statistical description of the gas is given. Conditions under which the Bousso bound can be violated are discussed and it is shown that a possible violating region cannot be arbitrarily large and it is contained inside a sphere of unit Planck radius if number of independent polarization states $g_s$ is small enough. It is also shown that central temperature must exceed the Planck temperature to get a violation of the Bousso bound for $g_s$ not too large.Comment: 14 pages, 4 figures, a paragraph added, version published in Gen. Rel. Gra

Walking the Walk or Just Talk?: A Global Examination of Men’s Intentions to Take Violence Preventative Action

Given the increasing prominence of both bystander-based approaches to gender-based violence (GBV) prevention and of proactively engaging men and boys to join efforts to end GBV, understanding the factors that support men’s antiviolence bystander behavior is important. This study examined correlates of willingness to engage in violence preventative bystander behavior in a global sample of 299 adult men engaged in GBV prevention events or work. Participants came from over 50 countries and provided data via an online, anonymous survey available in English, Spanish, and French. Path analysis was used to model participants’ willingness to engage in a variety of violence-preventative behaviors in the future, with variable selection guided by the Theory of Planned Behavior (TPB) and by research implicating gender-related attitudes in bystander willingness and behavior. Findings suggest that bystander willingness was supported by past bystander behavior, self-efficacy to engage in bystander behavior, positive beliefs about the contributions of antiviolence involvement, and by an awareness of male privilege. Social network support for GBV prevention work, and support for gender equity were not significant correlates of bystander willingness in the full path model. These findings held across participants from the Global North and Global South, suggesting that self-efficacy, an awareness of male privilege, and positive attitudes toward antiviolence work are factors which may support men’s violence preventative actions across broad regional contexts. © 2018 Taylor & Franci

Examining Men’s Perceptions of GBV Prevention Programming Content

As global efforts to engage men in preventing gender-based violence (GBV) continue to grow, understanding male participants’ perceptions of prevention events is needed. Data from a global sample of 319 men who had attended GBV prevention events were used to (a) assess men’s perceptions of what topics were covered, (b) determine whether profiles of these perceptions could be identified, and (c) describe the degree to which content prerception profiles are associated with levels of men’s motivation and confidence related to antiviolence action. Latent class analysis identified four perception profiles of prevention topics. Implications for GBV prevention programming are discussed. © The Author(s) 2018

Progress On The Paternal Brain: Theory, Animal Models, Human Brain Research, And Mental Health Implications

With a secure foundation in basic research across mammalian species in which fathers participate in the raising of young, novel brain‐imaging approaches are outlining a set of consistent brain circuits that regulate paternal thoughts and behaviors in humans. The newest experimental paradigms include increasingly realistic baby‐stimuli to provoke paternal cognitions and behaviors with coordinated hormone measures to outline brain networks that regulate motivation, reflexive caring, emotion regulation, and social brain networks with differences and similarities to those found in mothers. In this article, on the father brain, we review all brain‐imaging studies on PubMed to date on the human father brain and introduce the topic with a selection of theoretical models and foundational neurohormonal research on animal models in support of the human work. We discuss potentially translatable models for the identification and treatment of paternal mood and father–child relational problems, which could improve infant mental health and developmental trajectories with potentially broad public health importance. RESUMEN Con fundación segura en la investigación básica a través de las especies mamíferas en las que los padres participan en la crianza de sus pequeños, los novedosos acercamientos en el campo de imágenes cerebrales están definiendo un grupo de circuitos cerebrales consistentes que regulan los pensamientos y conductas paternas en los humanos. El más reciente paradigma experimental incluye cada vez más estímulos realistas al bebé para provocar percepciones y conductas paternas con medidas hormonales coordinadas para delinear las redes cerebrales que regulan la motivación, el cuidado reflexivo, la regulación de la emoción y las redes cerebrales sociales, con diferencias y similitudes a las que se presentan en las madres. En este artículo sobre el cerebro del padre, revisamos todos los estudios de imágenes cerebrales en PubMed hasta la fecha sobre el cerebro humano del padre e introducimos el tema con una selección de modelos teóricos y una básica investigación neuro‐hormonal en modelos animales como apoyo al trabajo humano. Discutimos modelos potencialmente transferibles para la identificación y tratamiento de problemas de estado de humor y de relación padre‐hijo, lo cual pudiera mejorar la salud mental infantil y las trayectorias de desarrollo con una potencial amplia importancia de salud pública. RÉSUMÉ Avec une fondation solide en recherches de base au travers des espèces de mammifères dans laquelle les pères participent à l’éducation des jeunes, des nouvelles approachs d’imagerie exposent un groupe de circuits du cerveau constants qui régulent les pensées paternelles et les comportements chez les humains. Les nouveaux paradigmes expérimentaux incluent des bébé‐stimulus de plus en plus réalistes pour provoquer des cognitions et des comportements paternels avec des mesures d’hormones coordonnées afin de souligner les réseaux qui régulent la motivation, le soin réfléchi, la régulation de l’émotion et les réseaux sociaux du cerveau avec les différences et les similarités que l’on trouve chez les mères. Dans cet article sur le cerveau du père, nous passons en revue toutes les études d’imagerie cérébrale trouvées par le moteur de recherche PubMed qui existent sur le cerveau humain du père et nous présentons le sujet au moyen d’une sélection de modèles théoriques et de recherches en matière neurohomormonale fondamentale chez des modèles animaux pour soutenir le travail sur l’humain. Nous discutons des modèles que l’on pourrait traduire pour l’identification et le traitement de l’humeur paternelle et les problèmes relationnels père‐enfant, qui pourraient améliorer la santé mentale du nourrisson et les trajectoires de développement cela pouvant avoir à la clé une grande importance pour la santé publique. ZUSAMMENFASSUNG Mit einem sicheren Fundament in der Grundlagenforschung über Säugetierarten, tragen Väter zu der Entwicklung von jungen, neuartigen bildgebenden Ansätzen bei, indem eine Reihe von konsistenten neuronalen Verschaltungen skizziert wird, die väterliche Gedanken und Verhaltensweisen beim Menschen regulieren. Die neuesten experimentellen Paradigmen nutzen realistische Säuglings‐Stimuli, um väterliche Kognitionen und Verhaltensweisen hervorzurufen, um mit abgestimmten Hormonerfassungen Netzwerke im Gehirn zu skizzieren, die Motivation, reflexive Fürsorge, Emotionsregulation und soziale Netzwerke im Gehirn regulieren. Diese sollen hinsichtlich Unterschieden und Ähnlichkeiten zu denen bei Müttern gefundenen Netzwerken betrachtet werden. In diesem Artikel zum Gehirn des Vaters, bieten wir einen Überblick über alle aktuellen bildgebenden Studien auf Pubmed über das menschliche Gehirn des Vaters und führen mit einer Auswahl von theoretischen Modellen und grundlegender neurohormonaler Forschung an Tiermodellen zur Unterstützung der menschlichen Arbeit in das Thema ein. Wir diskutieren potenziell übersetzbare Modelle für die Erkennung und Behandlung der väterlichen Stimmung und von Vater‐Kind‐Beziehungsproblemen, welche die psychische Gesundheit von Säuglingen und Entwicklungsverläufe mit potenziell großer Bedeutung für die öffentliche Gesundheit verbessern könnten. ABSTRACT 抄録：父親が幼い子育てに参加するほ乳類全体にわたる基礎研究での強固な基盤とともに、新しい脳画像アプローチによって、人類における父親の思考と行動を調節する一連の一貫した脳回路の輪郭が描かれつつある。母親に見られたものとの共通点と相違点とともに、動機、リフレクティブな養育、情緒調節を調節する脳のネットワーク、および社会脳のネットワークの輪郭を描くために、最新の実験パラダイムには、協調的なホルモンの測定とともに、父親の認知と行動を引き起こすための、ますます現実的な赤ちゃんの刺激が含まれる。父親の脳についてのこの論文では、私たちは今日までの人間の父親の脳についての pubmed にある全ての脳画像研究をレビューする。そして、人間の研究を支援して、選択した理論的モデルと、動物モデルについての基礎的神経内分泌研究のトピックを紹介する。私たちは、父親の気分と父子関係の問題を同定し治療するための、翻訳可能なモデルを考察する。それは、幅広い公衆衛生の重要性を持つ可能性のある、乳幼児精神保健と発達の軌跡を向上させるだろう。Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108662/1/imhj21471.pd

Einstein energy associated with the Friedmann -Robertson -Walker metric

Following Einstein's definition of Lagrangian density and gravitational field energy density (Einstein, A., Ann. Phys. Lpz., 49, 806 (1916); Einstein, A., Phys. Z., 19, 115 (1918); Pauli, W., {\it Theory of Relativity}, B.I. Publications, Mumbai, 1963, Trans. by G. Field), Tolman derived a general formula for the total matter plus gravitational field energy ($P_0$) of an arbitrary system (Tolman, R.C., Phys. Rev., 35(8), 875 (1930); Tolman, R.C., {\it Relativity, Thermodynamics & Cosmology}, Clarendon Press, Oxford, 1962)); Xulu, S.S., arXiv:hep-th/0308070 (2003)). For a static isolated system, in quasi-Cartesian coordinates, this formula leads to the well known result $P_0 = \int \sqrt{-g} (T_0^0 - T_1^1 -T_2^2 -T_3^3) ~d^3 x$, where $g$ is the determinant of the metric tensor and $T^a_b$ is the energy momentum tensor of the {\em matter}. Though in the literature, this is known as "Tolman Mass", it must be realized that this is essentially "Einstein Mass" because the underlying pseudo-tensor here is due to Einstein. In fact, Landau -Lifshitz obtained the same expression for the "inertial mass" of a static isolated system without using any pseudo-tensor at all and which points to physical significance and correctness of Einstein Mass (Landau, L.D., and Lifshitz, E.M., {\it The Classical Theory of Fields}, Pergamon Press, Oxford, 2th ed., 1962)! For the first time we apply this general formula to find an expression for $P_0$ for the Friedmann- Robertson -Walker (FRW) metric by using the same quasi-Cartesian basis. As we analyze this new result, physically, a spatially flat model having no cosmological constant is suggested. Eventually, it is seen that conservation of $P_0$ is honoured only in the a static limit.Comment: By mistake a marginally different earlier version was loaded, now the journal version is uploade

Energy and Momentum densities of cosmological models, with equation of state ρ=μ\rho=\mu, in general relativity and teleparallel gravity

We calculated the energy and momentum densities of stiff fluid solutions, using Einstein, Bergmann-Thomson and Landau-Lifshitz energy-momentum complexes, in both general relativity and teleparallel gravity. In our analysis we get different results comparing the aforementioned complexes with each other when calculated in the same gravitational theory, either this is in general relativity and teleparallel gravity. However, interestingly enough, each complex's value is the same either in general relativity or teleparallel gravity. Our results sustain that (i) general relativity or teleparallel gravity are equivalent theories (ii) different energy-momentum complexes do not provide the same energy and momentum densities neither in general relativity nor in teleparallel gravity. In the context of the theory of teleparallel gravity, the vector and axial-vector parts of the torsion are obtained. We show that the axial-vector torsion vanishes for the space-time under study.Comment: 15 pages, no figures, Minor typos corrected; version to appear in International Journal of Theoretical Physic

Energy and Momentum Distributions of Kantowski and Sachs Space-time

We use the Einstein, Bergmann-Thomson, Landau-Lifshitz and Papapetrou energy-momentum complexes to calculate the energy and momentum distributions of Kantowski and Sachs space-time. We show that the Einstein and Bergmann-Thomson definitions furnish a consistent result for the energy distribution, but the definition of Landau-Lifshitz do not agree with them. We show that a signature switch should affect about everything including energy distribution in the case of Einstein and Papapetrou prescriptions but not in Bergmann-Thomson and Landau-Lifshitz prescriptions.Comment: 12 page

Energy Distribution associated with Static Axisymmetric Solutions

This paper has been addressed to a very old but burning problem of energy in General Relativity. We evaluate energy and momentum densities for the static and axisymmetric solutions. This specializes to two metrics, i.e., Erez-Rosen and the gamma metrics, belonging to the Weyl class. We apply four well-known prescriptions of Einstein, Landau-Lifshitz, Papaterou and M$\ddot{o}$ller to compute energy-momentum density components. We obtain that these prescriptions do not provide similar energy density, however momentum becomes constant in each case. The results can be matched under particular boundary conditions.Comment: 18 pages, accepted for publication in Astrophysics and SpaceScienc

Interior of a Schwarzschild black hole revisited

The Schwarzschild solution has played a fundamental conceptual role in general relativity, and beyond, for instance, regarding event horizons, spacetime singularities and aspects of quantum field theory in curved spacetimes. However, one still encounters the existence of misconceptions and a certain ambiguity inherent in the Schwarzschild solution in the literature. By taking into account the point of view of an observer in the interior of the event horizon, one verifies that new conceptual difficulties arise. In this work, besides providing a very brief pedagogical review, we further analyze the interior Schwarzschild black hole solution. Firstly, by deducing the interior metric by considering time-dependent metric coefficients, the interior region is analyzed without the prejudices inherited from the exterior geometry. We also pay close attention to several respective cosmological interpretations, and briefly address some of the difficulties associated to spacetime singularities. Secondly, we deduce the conserved quantities of null and timelike geodesics, and discuss several particular cases in some detail. Thirdly, we examine the Eddington-Finkelstein and Kruskal coordinates directly from the interior solution. In concluding, it is important to emphasize that the interior structure of realistic black holes has not been satisfactorily determined, and is still open to considerable debate.Comment: 15 pages, 7 figures, Revtex4. V2: Version to appear in Foundations of Physic

Energy and Momentum Densities Associated with Solutions Exhibiting Directional Type Singularities

We obtain the energy and momentum densities of a general static axially symmetric vacuum space-time described by the Weyl metric, using Landau-Lifshitz and Bergmann-Thomson energy-momentum complexes. These two definitions of the energy-momentum complex do not provide the same energy density for the space-time under consideration, while give the same momentum density. We show that, in the case of Curzon metric which is a particular case of the Weyl metric, these two definitions give the same energy only when $R \to \infty$. Furthermore, we compare these results with those obtained using Einstein, Papapetrou and M{\o}ller energy momentum complexes.Comment: 10 pages, references added, minor corrections [Admin note: substantial overlap with gr-qc/0403097 , gr-qc/0403039