scholarly journals Hydrodynamic fluctuations from a weakly coupled scalar field

Author(s):  
G. Jackson ◽  
M. Laine
2008 ◽  
Vol 670 (1) ◽  
pp. 18-21 ◽  
Author(s):  
Jiunn-Wei Chen ◽  
Mei Huang ◽  
Yen-Han Li ◽  
Eiji Nakano ◽  
Di-Lun Yang

2013 ◽  
Vol 28 (20) ◽  
pp. 1350089 ◽  
Author(s):  
HYEONG-CHAN KIM

We study an inflation mechanism based on attractor properties in cosmological evolutions of a spatially flat Friedmann–Robertson–Walker spacetime based on the Einstein-scalar field theory. We find a new way to get the Hamilton–Jacobi equation solving the field equations. The equation relates a solution "generating function" with the scalar potential. We analyze its stability and find a later time attractor which describes a Universe approaching to an eternal-de Sitter inflation driven by the potential energy, V0>0. The attractor exists when the potential is regular and does not have a linear and quadratic terms of the field. When the potential has a mass term, the attractor exists if the scalar field is in a symmetric phase and is weakly coupled, λ<9V0/16. We also find that the attractor property is intact under small modifications of the potential. If the scalar field has a positive mass-squared or is strongly coupled, there exists a quasi-attractor. However, the quasi-attractor property disappears if the potential is modified. On the whole, the appearance of the eternal inflation is not rare in scalar cosmology in the presence of an attractor.


2002 ◽  
Vol 75 (6) ◽  
pp. 613 ◽  
Author(s):  
Stefano Santabarbara ◽  
Ilaria Cazzalini ◽  
Andrea Rivadossi ◽  
Flavio M. Garlaschi ◽  
Giuseppe Zucchelli ◽  
...  

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Yoan Martínez Márquez ◽  
Yalice Gámez Batista ◽  
Norberto Valcárcel Izquierdo

Las TIC median las interacciones y la comunicación de los estudiantes a diario. Se conciben como mediado-ras de la reflexión y la autorregulación de la actividad del estudiante, resultante de la interacción consciente de la percepción que tiene el estudiante sobre si con la que negocia con el resto de los estudiantes, los ase-sores y la sociedad en general. En este contexto el aprovechamiento de las TIC debe promover una influen-cia formativa en los espacios formales y no formales. Las condicionantes de complementariedad de espa-cios y de unidad en la diversidad de recursos tecnológicos y didácticos deben guiar la actividad que tenga al estudiante como centro de la misma.Ya no se trata de integrar las TIC en el proceso de formación, haciéndolo formal y estandarizado. El reto está en que sean las características personales de los estudiantes, sus estilos de aprendizaje, sus conoci-mientos y experiencias previas, y sus esquemas afectivos los que marquen el aprovechamiento de las TIC en la evaluación del aprendizaje autónomo de inglés.En el presente trabajo se estructura el aprovechamiento de las TIC mediante un EPA base para la evalua-ción del aprendizaje autónomo de inglés. El EPA base constituye un andamiaje de personas, procedimien-tos, espacios de interacción, y de recursos tecnológicos y didácticos. Los componentes que lo conforman se encuentran débilmente acoplados por la tecnología y altamente cohesionados por la significatividad de las conexiones que el estudiante establece entre ellos. Palabras Clave: Aprendizaje, Autonomía, Entorno, Evaluación, Personal. ABSTRACT There is no doubt about the key role of ICT in the interaction and communication processes among students. ICT are thought as a mean for the reflection and self-regulation of students´ activity, which is in a permanent conscientious comparison between the perception a student has about him/herself and the one he/she nego-tiates with the rest of students, advisors and society in general terms. In this context, ICT should promote a positive influence on student formation in formal and non-formal spaces. The conditionals related to spaces combined support and union in the diversity of technological and didactical resources should guide every activity having students at the center of its conception.It is no longer about integrating ICT to the formation process making it formal and standardized. The chal-lenge on autonomous language learning evaluation with ICT has to do with making the differences through personal characteristics of students, their learning styles, previous experiences and affective schemas.In this paper the use of ICT is structured by means of a PLE frame for the evaluation of English autonomous language learning. It is a scaffolding of people, procedures, interaction spaces, and technological and didac-tical resources. Its components are weakly coupled by technologies and highly cohesive by the meaningful connections students establish among them. Keywords: Learning, Autonomy, Evaluation, Environment, Personal. Recibido: septiembre de 2016Aprobado: noviembre de 2016


2018 ◽  
Author(s):  
Nicolò Bontempi ◽  
Irene Vassalini ◽  
Stefano Danesi ◽  
Matteo Ferroni ◽  
Paolo Colombi ◽  
...  

<p>Here we investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si core/shell microbeads (Si-rex) irradiated with three common Raman laser sources (lambda=532, 633, 785 nm) under real working conditions. We obtained an experimental proof of the critical role played by bead size and aggregation in heat and light management, demonstrating that in the case of strong opto-thermal coupling the temperature can exceed that of the melting points of both core and shell components. In addition, we also show that weakly coupled beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>


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