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We exhibit a characteristic structure of the class of all regular graphs of degree d that stems from the spectra of their adjacency matrices. The structure has a fractal threadlike appearance. Points with coordinates given by the mean and…

Combinatorics · Mathematics 2007-08-30 V. Ejov , J. A. Filar , S. K. Lucas , P. Zograf

Studies of the Universe's transition to smoothness in the context of LCDM have all pointed to a transition radius no larger than ~300 Mpc. These are based on a broad array of tracers for the matter power spectrum, including galaxies,…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-15 Fulvio Melia

A class of simplified measures is constructed to capture the key features of generic spatio-temporally chaotic systems. A combined analytical and numerical investigation allows us to extablish the scaling beahviour of the fractal dimension…

chao-dyn · Physics 2009-10-31 Antonio Politi , Annette Witt

The basic scaling laws for structures in a fractal universe require that the characteristic quantity of action associated with astronomical bodies should be of order near the maximum possible action allowed by the holographic upper bound.…

General Physics · Physics 2008-08-13 Scott Funkhouser

The distribution of visible matter in the universe, such as galaxies and galaxy clusters, has its origin in the week fluctuations of density that existed at the epoch of recombination. The hierarchical distribution of the universe, with its…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-21 Bruce N. Miller , Jean-Louis Rouet , Yui Shiozawa

We propose a new dynamical picture of galactic stellar and gas spirals, based on hydrodynamic simulations in a `live' stellar disk. We focus especially on spiral structures excited in a isolated galactic disk without a stellar bar. Using…

Astrophysics of Galaxies · Physics 2015-05-27 Keiichi Wada , Junichi Baba , Takayuki R. Saitoh

From a fractal perspective, the entropy bound of gravitational systems undergoes changes. Furthermore, in the cosmological setting, the conservation law of a perfect fluid is also altered in such systems, affecting spatial elements like…

General Relativity and Quantum Cosmology · Physics 2024-04-11 R. Jalalzadeh , S. Jalalzadeh , A. Sayahian Jahromi , H. Moradpour

The fractal properties of models of randomly placed $n$-dimensional spheres ($n$=1,2,3) are studied using standard techniques for calculating fractal dimensions in empirical data (the box counting and Minkowski-sausage techniques). Using…

Condensed Matter · Physics 2009-10-28 Daniel A. Hamburger , Ofer Biham , David Avnir

We review progress in numerical simulations of star cluster formation. These simulations involve the bottom-up assembly of clusters through hierarchical mergers, which produces a fractal stellar distribution at young (~0.5 Myr) ages. The…

Astrophysics of Galaxies · Physics 2015-05-14 Cathie Clarke

The interstellar medium has a highly filamentary and hierarchical structure, which may play a significant role in star formation. A systematical study on the large-scale filaments towards their physical parameters, distribution, structures…

Astrophysics of Galaxies · Physics 2022-01-06 Yifei Ge , Ke Wang

We discuss HD and MHD compressible turbulence as a cloud-forming and cloud-structuring mechanism in the ISM. Results from a numerical model of the turbulent ISM at large scales suggest that the phase-like appearance of the medium, the…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni

Fractals are measurable metric sets with non-integer Hausdorff dimensions. If electric and magnetic fields are defined on fractal and do not exist outside of fractal in Euclidean space, then we can use the fractional generalization of the…

High Energy Physics - Theory · Physics 2015-03-11 Vasily E. Tarasov

The galactic supershells are cavities in the interstellar medium. These shells can be explained by introducing the concept of superbubbles, the theoretical result of multiple supernova. The superbubbles can be analytically described if the…

Astrophysics · Physics 2015-06-24 Lorenzo Zaninetti

It is shown that the observed fractal distribution of galaxies is, in fact, consistent with homogeneity of the Universe and observational limits on $ \Delta T/T$, if the presence of dark matter and dark charge predicted by the Modified…

Astrophysics · Physics 2009-11-07 A. A. Kirillov

There exists a number of astronomical spectral phenomena that have remained unidentified after decades of extensive observations. The diffuse interstellar bands, the 220 nm feature, unidentified infrared emission bands, extended red…

Astrophysics of Galaxies · Physics 2021-08-11 Sun Kwok

This work examines a relativistic model for the observed inhomogeneities of the large scale structure where the hypothesis that this structure can be described as being a self-similar fractal system is advanced. The concept of hierarchical…

Astrophysics · Physics 2011-02-11 Marcelo B. Ribeiro

We consider the concept of fractons, i.e. particles or quasiparticles which obey specific fractal distribution function and for each universal class h of particles we obtain a fractal-deformed Heisenberg algebra. This one takes into account…

High Energy Physics - Theory · Physics 2007-05-23 Wellington da Cruz

We investigate the geometry of a critical system undergoing a second order thermal phase transition. Using a local description for the dynamics characterizing the system at the critical point T=Tc, we reveal the formation of clusters with…

High Energy Physics - Phenomenology · Physics 2009-10-31 N. G. Antoniou , Y. F. Contoyiannis , F. K. Diakonos

Certain dust particles in space are expected to appear as clusters of individual grains. The morphology of these clusters could be fractal or compact. To determine how these structural features would affect the interpretation of the…

Astrophysics · Physics 2007-05-23 A. C. Andersen , J. A. Sotelo , V. N. Pustovit , G. A. Niklasson

Using high resolution, two-dimensional hydrodynamical simulations, we investigate the evolution of a self-gravitating multi-phase interstellar medium in the central kiloparsec region of a galactic disk. We find that a gravitationally and…

Astrophysics · Physics 2009-10-31 Keiichi Wada , C. A. Norman