Scale Invariance Induced by Non-Linear Growth of Density Fluctuations

1991 ◽  
pp. 469-470
Author(s):  
F. Moutarde ◽  
J.-M. Alimi ◽  
F. R. Bouchet ◽  
R. Pellat
Keyword(s):  
Scale Invariance ◽  
Linear Growth ◽  
Density Fluctuations ◽  
Non Linear

scholarly journals Gravity and the non-linear growth of structure in the Carnegie-Spitzer-IMACS Redshift Survey

2020 ◽  
Vol 494 (2) ◽  
pp. 2628-2640 ◽  
Author(s):  
Daniel D Kelson ◽  
Louis E Abramson ◽  
Andrew J Benson ◽  
Shannon G Patel ◽  
Stephen A Shectman ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Linear Growth ◽  
Real Space ◽  
Density Fluctuations ◽  
Analytic Description ◽  
Newtonian Gravity ◽  
Density Growth ◽  
Non Linear ◽  
Redshift Survey ◽  
Analytic Prediction

ABSTRACT A key obstacle to developing a satisfying theory of galaxy evolution is the difficulty in extending analytic descriptions of early structure formation into full non-linearity, the regime in which galaxy growth occurs. Extant techniques, though powerful, are based on approximate numerical methods whose Monte Carlo-like nature hinders intuition building. Here, we develop a new solution to this problem and its empirical validation. We first derive closed-form analytic expectations for the evolution of fixed percentiles in the real-space cosmic density distribution, averaged over representative volumes observers can track cross-sectionally. Using the Lagrangian forms of the fluid equations, we show that percentiles in δ – the density relative to the median – should grow as $\delta (t)\propto \delta _{0}^{\alpha }\, t^{\beta }$, where α ≡ 2 and β ≡ 2 for Newtonian gravity at epochs after the overdensities transitioned to non-linear growth. We then use 9.5 square degress of Carnegie-Spitzer-IMACS Redshift Survey data to map galaxy environmental densities over 0.2 < z < 1.5 (∼7 Gyr) and infer α = 1.98 ± 0.04 and β = 2.01 ± 0.11 – consistent with our analytic prediction. These findings – enabled by swapping the Eulerian domain of most work on density growth for a Lagrangian approach to real-space volumetric averages – provide some of the strongest evidence that a lognormal distribution of early density fluctuations indeed decoupled from cosmic expansion to grow through gravitational accretion. They also comprise the first exact, analytic description of the non-linear growth of structure extensible to (arbitrarily) low redshift. We hope these results open the door to new modelling of, and insight-building into, galaxy growth and its diversity in cosmological contexts.

Internal GIG Ecosystem in IT/ITeS Organisations for Non-linear Growth

2021 ◽  
pp. 232209372110132
Author(s):  
Debolina Dutta ◽  
Prem Mirchandani ◽  
K. P. Anasha
Keyword(s):  
Employee Satisfaction ◽  
Linear Growth ◽  
Growth Models ◽  
Global Scale ◽  
Growth Trajectory ◽  
It Services ◽  
Industry Growth ◽  
It Service ◽  
Significant Contributor ◽  
Non Linear

The Indian IT/ITeS industry is a significant contributor to India’s GDP and has had an impressive growth trajectory. However, it continues to be plagued with talent shortages, managing employee satisfaction, growth aspirations and reducing attrition. COVID-19 has presented an unprecedented opportunity for IT service organisations to transform the established paradigm of working. The industry has been exploring non-linear growth models that address the talent demand-supply gap. With skilled talent shortage continuing to limit the industry growth, non-linear initiatives of growth are urgently required. We propose a model of ‘Internal Gig’ worker (I-GIG) for the IT services industry. The new I-GIG workforce would be providing non-linear outcomes without increasing costs significantly. We also argue that this model would be motivational for employees who opt for it, with commensurate reward motivations to engage them. Additionally, this model would enable the workanywhere, anytime and leverage talent availability on a global scale.

Bucking the Trend: A Look at Zyme Solutions' Non-linear Business Model for IT Services from India

2011 ◽  
Vol 15 (01) ◽  
pp. 37-62 ◽  
Author(s):  
D.V.R. Seshadri
Keyword(s):  
Business Model ◽  
Service Provider ◽  
Business Models ◽  
Linear Growth ◽  
High Tech ◽  
Data Service ◽  
It Services ◽  
Software Companies ◽  
Non Linear ◽  
Vertical Market

The case describes XGen Technologies (name disguised), an India-based IT Enabled Services (ITES) company having to grapple with the issues of linear growth. The company's headcount had touched a whopping 40,000 and managing such a large setup was becoming a severe challenge, putting immense pressure on Partha Sen, the CEO, to adopt an innovative business model to sustain historical growth rates of revenue and profitability. This situation was similar to what most Indian ITES companies faced: they had been clocking impressive growth, yet there were concerns about the future. The case then describes some of the strategies that software companies have been adopting in order to achieve greater non-linearity in their business. In particular, the case concentrates on Zyme Solutions, Inc., a fully outsourced hosted data service provider to the high-tech vertical market, which has built as a non-linear business from the ground up, without the legacy of the linear business models to contend with. Students are put in the place of Partha Sen, having to decide on an approach that established companies like XGen could adopt to transit to a non-linear model.

Non-linear growth trends of toe flexor muscle strength among children, adolescents, and young adults: a cross-sectional study

2018 ◽  
Vol 118 (5) ◽  
pp. 1003-1010 ◽  
Author(s):  
Noriteru Morita ◽  
Junichiro Yamauchi ◽  
Ryosuke Fukuoka ◽  
Toshiyuki Kurihara ◽  
Mitsuo Otsuka ◽  
...  
Keyword(s):  
Young Adults ◽  
Muscle Strength ◽  
Linear Growth ◽  
Cross Sectional Study ◽  
Adolescents And Young Adults ◽  
Sectional Study ◽  
Flexor Muscle ◽  
Cross Sectional ◽  
Growth Trends ◽  
Non Linear

scholarly journals Kinetic field theory: Non-linear cosmic power spectra in the mean-field approximation

2021 ◽  
Vol 10 (6) ◽  
Author(s):  
Matthias Bartelmann ◽  
Johannes Dombrowski ◽  
Sara Konrad ◽  
Elena Kozlikin ◽  
Robert Lilow ◽  
...  
Keyword(s):  
Field Theory ◽  
Power Spectrum ◽  
Mean Field ◽  
Power Spectra ◽  
Field Approximation ◽  
Density Fluctuations ◽  
Mean Field Approximation ◽  
Non Linear ◽  
Two Parameters ◽  
Kinetic Field

We use the recently developed Kinetic Field Theory (KFT) for cosmic structure formation to show how non-linear power spectra for cosmic density fluctuations can be calculated in a mean-field approximation to the particle interactions. Our main result is a simple, closed and analytic, approximate expression for this power spectrum. This expression has two parameters characterising non-linear structure growth which can be calibrated within KFT itself. Using this self-calibration, the non-linear power spectrum agrees with results obtained from numerical simulations to within typically \lesssim10\,\%≲10% up to wave numbers k\lesssim10\,h\,\mathrm{Mpc}^{-1}k≲10hMpc−1 at redshift z = 0z=0. Adjusting the two parameters to optimise agreement with numerical simulations, the relative difference to numerical results shrinks to typically \lesssim 5\,\%≲5%. As part of the derivation of our mean-field approximation, we show that the effective interaction potential between dark-matter particles relative to Zel’dovich trajectories is sourced by non-linear cosmic density fluctuations only, and is approximately of Yukawa rather than Newtonian shape.

scholarly journals Non-linear evolution of the resonant drag instability in magnetized gas

2019 ◽  
Vol 485 (3) ◽  
pp. 3991-3998 ◽  
Author(s):  
Darryl Seligman ◽  
Philip F Hopkins ◽  
Jonathan Squire
Keyword(s):  
Linear Theory ◽  
Coherent Structures ◽  
Magnetic Energy ◽  
Density Fluctuations ◽  
Linear Evolution ◽  
Drag Forces ◽  
Non Linear ◽  
Magnetohydrodynamic Simulations ◽  
First Time ◽  
Different Parts

Abstract We investigate, for the first time, the non-linear evolution of the magnetized ‘resonant drag instabilities’ (RDIs). We explore magnetohydrodynamic simulations of gas mixed with (uniform) dust grains subject to Lorentz and drag forces, using the gizmo code. The magnetized RDIs exhibit fundamentally different behaviour than purely acoustic RDIs. The dust organizes into coherent structures and the system exhibits strong dust–gas separation. In the linear and early non-linear regime, the growth rates agree with linear theory and the dust self-organizes into 2D planes or ‘sheets.’ Eventually the gas develops fully non-linear, saturated Alfvénic, and compressible fast-mode turbulence, which fills the underdense regions with a small amount of dust, and drives a dynamo that saturates at equipartition of kinetic and magnetic energy. The dust density fluctuations exhibit significant non-Gaussianity, and the power spectrum is strongly weighted towards the largest (box scale) modes. The saturation level can be understood via quasi-linear theory, as the forcing and energy input via the instabilities become comparable to saturated tension forces and dissipation in turbulence. The magnetized simulation presented here is just one case; it is likely that the magnetic RDIs can take many forms in different parts of parameter space.

scholarly journals Application of Non-linear Growth Curve Models to Body Weight in Egg-type Chicken.

1995 ◽  
Vol 32 (6) ◽  
pp. 394-401 ◽  
Author(s):  
Shunzo MIYOSHI ◽  
Mitsuyoshi SUZUKI ◽  
Takatsugu MITSUMOTO
Keyword(s):  
Body Weight ◽  
Growth Curve ◽  
Linear Growth ◽  
Growth Curve Models ◽  
Non Linear ◽  
Linear Growth Curve
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