scholarly journals Time Variable Λ and the Accelerating Universe

2010 ◽  
Vol 50 (3) ◽  
pp. 752-759 ◽  
Author(s):  
Utpal Mukhopadhyay ◽  
Saibal Ray ◽  
A. A. Usmani ◽  
Partha Pratim Ghosh
2007 ◽  
Vol 16 (11) ◽  
pp. 1791-1802 ◽  
Author(s):  
SAIBAL RAY ◽  
UTPAL MUKHOPADHYAY ◽  
S. B. DUTTA CHOUDHURY

Two phenomenological models of Λ, viz. [Formula: see text] and [Formula: see text], are studied under the assumption that G is a time-variable parameter. Both models show that G is inversely proportional to time, as suggested earlier by others, including Dirac. The models considered here can be matched with observational results by properly tuning the parameters of the models. Our analysis shows that the [Formula: see text] model corresponds to a repulsive situation and hence correlates with the present status of the accelerating Universe. The other model, [Formula: see text], is in general attractive in nature. Moreover, it is seen that due to the combined effect of time-variable Λ and G the Universe evolved with acceleration as well as deceleration. Deceleration indicates a "big crunch".


2012 ◽  
Vol 21 (01) ◽  
pp. 1250005 ◽  
Author(s):  
JIANBO LU ◽  
LINA MA ◽  
MOLIN LIU ◽  
YABO WU

Time variable cosmological constant (TVCC) of holographic origin with interaction in Brans–Dicke theory is discussed in this paper. We investigate some characters for this model, and show the evolutions of deceleration parameter and equation of state (EOS) for dark energy. It is shown that in this scenario an accelerating universe can be obtained and the evolution of EOS for dark energy can cross over the boundary of phantom divide. In addition, a geometrical diagnostic method, jerk parameter, is applied to this model to distinguish it with cosmological constant.


1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.


1965 ◽  
Vol 04 (03) ◽  
pp. 136-140
Author(s):  
Cl Jeanty

A method is described in an attempt to make medical records suitable for epidemiologigri: purposes. Every case of a disease is recorded on an appropriate punched card with the object of working towards a general description of a disease through the collation of several cases of the same diagnosis. This punched card represents a very great condensation of the original record. Special care has been applied to state as precisely as possible the time variable, particularly as far as its origin and unit of measure are concerned, in order to demonstrate the existence of causal relations between diseases. Such cards are also intended to make easier statistical studies in clinical pathology, in evaluation of new laboratory techniques, and in therapeutical trials.


2016 ◽  
Vol 7 (2) ◽  
pp. 148-154
Author(s):  
Bimo Satriantoro ◽  
Ni Made Satvika Iswari

Indonesian people have a high interest for public transportation. There are few kind of public transportation, and taxi is one of them. Taxi use taximeter to calculate passanger fares. Taximeters between taxi companies are different in term of results although using the same equation and principle. The total fare from the taximeter is based on equation that includes distance variable, speed of the vehicle, and time variable. People have a problem to choose taxi because of the differnces of taximeter fares and taxi pool. Based on the problem, the solution is an application to help customer to decide choosing taxi. The application will help customer by giving informations about taximeter and carpool form two different company. The informations are based on the distance of the start point and the finish point of the customer and based on the distances of the customer and the carpool of the taxy company that will processed trough the application to calculating the total fares for the customer between two taxi companies. By using algorithm for linear searching, customer will get the informations to help them to decide which taxi the customer will use. Keywords: Linear Algorithm, Taximeter, Google Apps, Choice, Taxi


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