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We use a spatially resolved cavity ring-down technique to show that the 2D eigenmode of an unstable optical cavity has a fractal pattern, i.e. it looks the same at different length scales. In agreement with theory, we find that this pattern…

Optics · Physics 2007-05-23 Javier A. Loaiza , Eric R. Eliel , J. P. Woerdman

Fractal surfaces are ubiquitous in nature as well as in the sciences. The examples range from the cloud boundaries to the corroded surfaces. Fractal dimension gives a measure of the irregularity in the object under study. We present a…

Geophysics · Physics 2014-12-10 Kiran M. Kolwankar , Nakul N. Karle

In the interstellar medium of the Milky Way, certain elements -- e.g., Mg, Si, Al, Ca, Ti, Fe -- reside predominantly in interstellar dust grains. These grains absorb, scatter, and emit electromagnetic radiation, heat the interstellar…

Astrophysics · Physics 2007-05-23 B. T. Draine

Observations of H3+ in the Galactic diffuse interstellar medium (ISM) have led to various surprising results, including the conclusion that the cosmic-ray ionization rate (zeta_2) is about 1 order of magnitude larger than previously…

Astrophysics of Galaxies · Physics 2015-06-03 Nick Indriolo , Benjamin J. McCall

Using Monte Carlo simulations we study the distributions of the 3-block mass $N_3$ in 4d, 5d, and 6d percolation systems. Because the probability of creating large 3-blocks in these dimensions is very small, we use a ``go with the winners''…

Disordered Systems and Neural Networks · Physics 2009-11-07 Gerald Paul , H. Eugene Stanley

Perfect fractals are mathematical objects that, because they are generated by recursive processes, have self-similarity and infinite complexity. In particular, they also have a fractional dimension. Although several proposals for the study…

Physics Education · Physics 2018-04-04 P. V. S. Souza , R. L. Alves , W. F. Balthazar

I present an overview of the hierarchy of structures existing in the interstellar medium (ISM) and the possible mechanisms that cause the fragmentation of one level into the next, with the formation of stars as its last step. Within this…

Astrophysics · Physics 2009-11-10 Enrique Vazquez-Semadeni

We map the distribution and properties of the Milky Way's interstellar medium as traced by diffuse interstellar bands (DIBs) detected in near-infrared stellar spectra from the SDSS-III/APOGEE survey. Focusing exclusively on the strongest…

This work tests if the large-scale galaxy distribution can be characterized as a fractal system. The $\Lambda$CDM cosmology with $H_0=(70\pm 5)$ km/s/Mpc is adopted to study the UltraVISTA DR1, COSMOS2015 and SPLASH surveys, alongside the…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-03 Sharon Teles

A fractal surface is a set which is a graph of a bivariate continuous function. In the construction of fractal surfaces using IFS, vertical scaling factors in IFS are important one which characterizes a fractal feature of surfaces…

Dynamical Systems · Mathematics 2014-04-07 Chol-Hui Yun , Hui-Chol Choi , Hyong-Chol O

The possibility to constrain fractal space dimensionality from Astrophysics and other areas is briefly reviewed. Assuming such dimensionality to be $3 + \epsilon$, a limit to $\epsilon$ can be inferred from COBE satellite data. The…

Astrophysics · Physics 2021-10-19 Francisco Caruso , Vitor Oguri

This report focuses on the dependencies for the center and radius of the confidence interval that arise when estimating the mass fractal dimensions of isotropic sampling clusters in the site percolation model.

Statistical Mechanics · Physics 2011-10-07 P. V. Moskalev , K. V. Grebennikov , V. V. Shitov

We analyze the physical parameters of interstellar filaments that we describe by an idealized model of isothermal self-gravitating infinite cylinder in pressure equilibrium with the ambient medium. Their gravitational state is characterized…

Astrophysics of Galaxies · Physics 2015-06-04 Joerg Fischera , Peter G. Martin

Galaxy structures are certainly fractal up to a certain crossover scale \lambda_0. A clear determination of such a scale is still missing. Usually, the conceptual and practical implications of this property are neglected and the structures…

Astrophysics · Physics 2007-05-23 Luciano Pietronero , Francesco Sylos Labini

Spatial patterns and processes of cities can be described with various entropy functions. However, spatial entropy always depends on the scale of measurement, and it is difficult to find a characteristic value for it. In contrast, fractal…

Physics and Society · Physics 2018-12-19 Yanguang Chen , Jiejing Wang , Jian Feng

The thermal properties of star-forming clouds have an important influence on how they fragment into stars, and it is suggested in this paper that the low-mass stellar IMF, which appears to be almost universal, is determined largely by the…

Astrophysics · Physics 2011-05-05 Richard B. Larson

A \emph{fractal} is an object exhibiting complexity at arbitrarily small scales. In order to study and characterise fractals, one is often interested in quantifying how they fill up space on small scales. This gives rise to various notions…

Classical Analysis and ODEs · Mathematics 2026-03-12 Jonathan M. Fraser

This paper studies the effect of the distance choice in radial (non-average) statistical tools used for fractal characterization of galaxy distribution. After reviewing the basics of measuring distances of cosmological sources, various…

Astrophysics · Physics 2014-10-13 Marcelo B. Ribeiro

Despite the observational evidence that the Universe appears hierarchically structured up to a distance of at least 30 Mpc/h (and possibly up to 100 Mpc/h), the fractal paradigm has not yet been recognized by the majority of cosmologists…

General Physics · Physics 2009-07-14 P V Grujic , V D Pankovic

Many 0/1 datasets have a very large number of variables; on the other hand, they are sparse and the dependency structure of the variables is simpler than the number of variables would suggest. Defining the effective dimensionality of such a…

Machine Learning · Computer Science 2019-02-06 Nikolaj Tatti , Taneli Mielikainen , Aristides Gionis , Heikki Mannila
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