scholarly journals Role of dissipative effects in the quantum gravitational onset of warm Starobinsky inflation in a closed universe

2021 ◽  
Vol 104 (10) ◽  
Author(s):  
Meysam Motaharfar ◽  
Parampreet Singh
Keyword(s):  
Closed Universe ◽  
Dissipative Effects

scholarly journals Viscosity in cosmic fluids

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Pravin Kumar Natwariya ◽  
Jitesh R. Bhatt ◽  
Arun Kumar Pandey
Keyword(s):  
Dark Matter ◽  
Effective Viscosity ◽  
Large Scale ◽  
Significant Contribution ◽  
Viscosity Coefficient ◽  
Effective Theory ◽  
Viscous Effect ◽  
Dissipative Effects ◽  
Large Scale Structure Formation

Abstract The effective theory of large-scale structure formation based on $$\Lambda $$ΛCDM paradigm predicts finite dissipative effects in the resulting fluid equations. In this work, we study how viscous effect that could arise if one includes self-interaction among the dark-matter particles combines with the effective theory. It is shown that these two possible sources of dissipation can operate together in a cosmic fluid and the interplay between them can play an important role in determining dynamics of the cosmic fluid. In particular, we demonstrate that the viscosity coefficient due to self-interaction is added inversely with the viscosity calculated using effective theory of $$\Lambda $$ΛCDM model. Thus the larger viscosity has less significant contribution in the effective viscosity. Using the known bounds on $$\sigma /m$$σ/m for self-interacting darkmatter, where $$\sigma $$σ and m are the cross-section and mass of the dark-matter particles respectively, we discuss role of the effective viscosity in various cosmological scenarios.

Creation in a Closed Universe Or, Have Physicists Disproved the Existence of God?

1991 ◽  
Vol 27 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Robin Le Poidevin
Keyword(s):  
Temporal Structure ◽  
Closed Surface ◽  
Closed Universe ◽  
Existence Of God ◽  
Space And Time ◽  
Stephen Hawking ◽  
History Of ◽  
The Universe

Could a theory concerning the temporal structure of the universe have any implications for the possibility of a creator? A recent remark by Stephen Hawking suggests that it could. In A Brief History of Time, Hawking writes:The idea that space and time may form a closed surface without boundary … has profound implications for the role of God in the affairs of the universe… So long as the universe had a beginning, we could suppose it had a creator. But if the universe is really completely self-contained, having no boundary or edge, it would have neither beginning nor end: it would simply be. What place, then, for a creator?

The role of dissipation in macroscopic quantum tunneling and in near-field propagation

2019 ◽  
Vol 33 (11) ◽  
pp. 1950131
Author(s):  
A. Ranfagni ◽  
G. P. Pazzi ◽  
I. Cacciari
Keyword(s):  
Quantum Tunneling ◽  
Wave Attenuation ◽  
Near Field ◽  
Superconducting Devices ◽  
Transition Elements ◽  
Microwave Propagation ◽  
Dissipative Effects ◽  
Alternative Approach ◽  
Macroscopic Quantum Tunneling

A stochastic model, which demonstrated to be capable of determining dissipative effects in the microwave circuits loading superconducting devices, is found to be suitable also for analyzing near-field microwave propagation when the wave attenuation is interpreted as a dissipative effect. An alternative approach to the problem is offered by Feynman’s transition elements.

Modeling and Characterization of Rotary Electrohydrostatic Actuators

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Renato Galluzzi ◽  
Nicola Amati ◽  
Andrea Tonoli
Keyword(s):  
Bulk Modulus ◽  
Hydraulic Systems ◽  
Dynamic Characterization ◽  
Dissipative Effects

Electrohydrostatic actuators are increasingly finding applications in different fields due to their numerous advantages with respect to electromechanical and conventional hydraulic systems. To understand their behavior, potentialities, limitations, and design aspects, the present paper deals with the modeling of such devices. The discussed phenomena are experimentally validated through the stationary and dynamic characterization tests of a rotary electrohydrostatic prototype. Results emphasize the role of mechanical and hydraulic dissipative effects and the fluid bulk modulus.

scholarly journals Mixing by Internal Waves

1993 ◽  
Vol 137 ◽  
pp. 281-283
Author(s):  
Josefina Montalbán ◽  
Evry Schatzman
Keyword(s):  
Internal Waves ◽  
Spectral Type ◽  
Rotation Velocity ◽  
Lithium Abundance ◽  
Diffusive Process ◽  
Dissipative Effects ◽  
Non Linear ◽  
Radiative Zone

That mixing take place in the radiative zone of many stars, is an event that cannot be forgotten when we try to explain observational results as the lithium abundance in the atmosphere of different stars, its dependence on spectral type, age or rotation velocity... During the last years many processes have been proposed as being responsible of this mixing: overshooting, turbulence induced by rotational instabilities, internal waves, etc... We will consider, following the results obtained by Press (1981), the role of this last mechanism in the transport of lithium to the burning level, not as generators of turbulence (in Press, 1981, and García-López and Spruit, 1991, it is shown that turbulence induced by internal waves decays very quickly inside the radiative zone), but as generators of a diffusive process due to non linear dissipative effects.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of affect in feelings of obligation

2020 ◽  
Vol 43 ◽  
Author(s):  
Stefen Beeler-Duden ◽  
Meltem Yucel ◽  
Amrisha Vaish
Keyword(s):  
Positive Emotions ◽  
The Creation ◽  
Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

Sign in / Sign up

Export Citation Format

Share Document