The Schrödinger kernel of the twisted Laplacian and cyclic models

2010 ◽  
Vol 95 (6) ◽  
pp. 593-599 ◽  
Author(s):  
Shahla Molahajloo ◽  
M. W. Wong
Keyword(s):  
Twisted Laplacian ◽  
Cyclic Models

COSMOLOGICAL PERTURBATIONS: MYTHS AND FACTS

2004 ◽  
Vol 19 (13n16) ◽  
pp. 967-982 ◽  
Author(s):  
PAUL J. STEINHARDT
Keyword(s):  
Cosmological Perturbations ◽  
Cyclic Models

We discuss (and debunk) ten common myths about cosmological perturbations in inflationary and ekpyrotic/cyclic models and their implications for future observations.

scholarly journals Spectral projections for the twisted Laplacian

2007 ◽  
Vol 180 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Herbert Koch ◽  
Fulvio Ricci
Keyword(s):  
Twisted Laplacian ◽  
Spectral Projections

Modelling of Systems with Elements in Several States

2021 ◽  
Vol 17 ◽  
pp. 244-252
Author(s):  
Anna Tarasenko ◽  
Oleksandr Karelin ◽  
Manuel Gonzalez Hernández ◽  
Oleksandr Barabash
Keyword(s):  
Mortality Rate ◽  
Integral Equations ◽  
Equilibrium Position ◽  
Mutual Influence ◽  
Initial State ◽  
Final State ◽  
And Shifts ◽  
Cyclic Models

In this paper, we consider systems with one resource, which can be in several states. The states differ significantly in their processes of mortality, reproduction and mutual influence. For instance, infected elements can have a higher mortality rate than healthy and recovered ones. For cyclic models, in which the initial state of the system coincides with the final state, balance relations are found. They represent a system with functional operators with shift and integrals with degenerate kernels. Modified Fredholm method, proposed in previous works to solve the integral equations of the second type with degenerate kernels and shifts, is applied. Equilibrium position of a system with a three-state resource is found.

scholarly journals Desensitization of Mouse Nicotinic Acetylcholine Receptor Channels

1998 ◽  
Vol 112 (2) ◽  
pp. 181-197 ◽  
Author(s):  
Anthony Auerbach ◽  
Gustav Akk
Keyword(s):  
Acetylcholine Receptor ◽  
Rate Constant ◽  
Binding Sites ◽  
Single Channel ◽  
Ion Permeation ◽  
Activation Gate ◽  
The Status ◽  
Single Channel Currents ◽  
Cyclic Models ◽  
Channel Currents

The rate constants of acetylcholine receptor channels (AChR) desensitization and recovery were estimated from the durations and frequencies of clusters of single-channel currents. Diliganded-open AChR desensitize much faster than either unliganded- or diliganded-closed AChR, which indicates that the desensitization rate constant depends on the status of the activation gate rather than the occupancy of the transmitter binding sites. The desensitization rate constant does not change with the nature of the agonist, the membrane potential, the species of permeant cation, channel block by ACh, the subunit composition (ε or γ), or several mutations that are near the transmitter binding sites. The results are discussed in terms of cyclic models of AChR activation, desensitization, and recovery. In particular, a mechanism by which activation and desensitization are mediated by two distinct, but interrelated, gates in the ion permeation pathway is proposed.

scholarly journals A cyclic universe with varying cosmological constant in f(R, T) gravity

2019 ◽  
Vol 97 (10) ◽  
pp. 1075-1082 ◽  
Author(s):  
Nasr Ahmed ◽  
Sultan Z. Alamri
Keyword(s):  
Cosmological Constant ◽  
Early Time ◽  
State Parameter ◽  
Singular Values ◽  
Energy Conditions ◽  
Late Time ◽  
Time Varying ◽  
Causality Condition ◽  
Cyclic Universe ◽  
Cyclic Models

A new kind of evolution for cyclic models in which the Hubble parameter oscillates and remains positive has been explored in a specific f(R, T) gravity reconstruction. A singularity-free cyclic universe with negative varying cosmological constant has been obtained, which supports the role suggested for negative Λ in stopping the eternal acceleration. The cosmological solutions have been obtained for the case of a flat universe, supported by observations. The cosmic pressure grows without singular values; it is positive during the early-time decelerated expansion and negative during the late-time accelerating epoch. The time-varying equation of state parameter ω(t) shows quintom behavior and is restricted to the range –2.25 ≤ ω(t) ≲ 1/3. The validity of the classical linear energy conditions and the sound speed causality condition has been studied. The non-conventional mechanism of negative cosmological constant that are expected to address the late-time acceleration has been discussed.

scholarly journals Intuitive understanding of non-Gaussianity in ekpyrotic and cyclic models

2008 ◽  
Vol 78 (2) ◽  
Author(s):  
Jean-Luc Lehners ◽  
Paul J. Steinhardt
Keyword(s):  
Cyclic Models

β-Turns in serine-containing linear and cyclic models

Biopolymers ◽  
1987 ◽  
Vol 26 (9) ◽  
pp. 1527-1553 ◽  
Author(s):  
M. Hollósi ◽  
K. E. Kövér ◽  
S. Holly ◽  
G. D. Fasman
Keyword(s):  
Cyclic Models

Collaborative Research and Development: New Insights from Cyclic Models of the Innovation Process

1998 ◽  
Vol 02 (01) ◽  
pp. 107-121 ◽  
Author(s):  
John Steen ◽  
Dallas Hanson ◽  
Peter Liesch
Keyword(s):  
Research And Development ◽  
Collaborative Research ◽  
Linear Models ◽  
Innovation Process ◽  
Current Theory ◽  
Government Funding ◽  
Interactive Process ◽  
Codified Knowledge ◽  
Cyclic Models ◽  
Forms Of Knowledge

Traditional linear models of innovation, in which it is assumed that government funding of R&D will axiomatically create innovative industries, have become obsolete. This paper suggests that innovation is in fact a complex and interactive process that involves cycles of learning. However, these "knowledge cycle" models of innovation are largely unvalidated empirically and further research will be required to extend the current theory. Knowledge cycle models appear to be superior to the linear models for a number of reasons. These include major roles for tacit (uncodified) knowledge as well as explicit (codified) knowledge, which are largely ignored in linear innovation models. An emphasis upon iterative collaboration between firms and researchers and the importance of firms participating more directly in the research and development (R&D) process may enhance the utilisation of these forms of knowledge.

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