Related papers: Fossil Biodiversity: Red Noise Plus Signal
A simple model of macroevolution is proposed exhibiting both the property of punctuated equilibrium and the dynamics of potentialities for different species to evolve towards increasingly higher complexity. It is based on the phenomenon of…
We present a power spectrum analysis of the final 2dF Galaxy Redshift Survey, employing a direct Fourier method. The sample used comprises 221,414 galaxies with measured redshifts. We investigate in detail the modelling of the sample…
The 21-cm forest signal is a promising probe of the Epoch of Reionization complementary to other 21-cm line observables and Ly$\alpha$ forest signal. Prospects of detecting it have significantly improved in the last decade thanks to the…
The 2dF Galaxy Redshift Survey has now measured in excess of 160000 galaxy redshifts. This paper presents the power spectrum of the galaxy distribution, calculated using a direct FFT-based technique. We argue that, within the k-space region…
The transient behavior of an ecosystem with N random interacting species in the presence of a multiplicative noise is analyzed. The multiplicative noise mimics the interaction with the environment. We investigate different asymptotic…
We present a simple stochastic mechanism which generates pulse trains exhibiting a power law distribution of the pulse intervals and a $1/f^\alpha$ power spectrum over several decades at low frequencies with $\alpha$ close to one. The…
The detection of a stochastic gravitational wave background by pulsar-timing arrays indicates the presence of a population of supermassive black hole binaries. Although the observed spectrum generally matches predictions for orbital…
We present a study of the trends in luminosity, linear size, spectral index, and redshift of classical double radio sources from three complete samples selected at successively fainter low radio-frequency flux-limits. We have been able to…
Recent experiments on blinking quantum dots and weak turbulence in liquid crystals reveal the fundamental connection between $1/f$ noise and power law intermittency. The non-stationarity of the process implies that the power spectrum is…
We study the evolution of circumstellar disks in 22 young (1 to 100 Myr) nearby (within 500 pc) associations over the entire mass spectrum using photometry covering from the optical to the mid-infrared. We compiled a catalog of 2340…
Interest in understanding the interplay between noise and the response of a non-linear device cuts across disciplinary boundaries. It is as relevant for unmasking the dynamics of neurons in noisy environments as it is for designing reliable…
We re-analyse the subset of the Faraday rotation measures data from the NRAO VLA Sky Survey catalogue for which redshift and spectral index information is available, in order to better elucidate the relations between these observables. We…
We measure the power spectrum, P_F(k,z), of the transmitted flux in the Ly-alpha forest using 3035 high redshift quasar spectra from the Sloan Digital Sky Survey. This sample is almost two orders of magnitude larger than any previously…
The changes in brightness of an astronomical source as a function of time are key probes into that source's physics. Periodic and quasi-periodic signals are indicators of fundamental time (and length) scales in the system, while stochastic…
The orchestra performance is full of sublime rich sounds. In particular, the unison of violins sounds different from the solo violin. We try to clarify this difference and similarity of unison and solo numerically analyzing the beat of…
Highly-diverse ecosystems exhibit a broad distribution of population sizes and species turnover, where species at high and low abundances are exchanged over time. We show that these two features generically emerge in the fluctuating phase…
Fourier transform power spectra of major axis cuts in V and Halpha images were made for a sample of 9 irregular galaxies. These power spectra reveal structure over a wide range of scales. For 6 of the galaxies the power spectrum slopes at…
Many biological systems are appropriately viewed as passive inclusions immersed in an active bath: from proteins on active membranes to microscopic swimmers confined by boundaries. The non-equilibrium forces exerted by the active bath on…
Based on statistical analysis of the complete genome sequences, a remote relationship has been observed between the evolution of the genetic code and the three domain tree of life. The existence of such a remote relationship need to be…
We have analyzed the properties of low column density Lyman alpha forest clouds (12.8 < log N_HI < 16.0) toward 5 QSOs at different redshifts, using high signal-to-noise data from the HIRES spectrograph on the Keck I 10-m telescope. The…