We examine the nonlinear structure of gravitationally collapsed objects that form in our simulations of wavelike cold dark matter (ψDM), described by the Schrödinger-Poisson (SP) equation with a particle mass ∼ 10 −22 eV. A distinct gravitationally self-bound solitonic core is found at the center of every halo, with a profile quite different from cores modeled in the warm or self-interacting dark matter scenarios. Furthermore, we show that each solitonic core is surrounded by an extended halo composed of large fluctuating dark matter granules which modulate the halo density on a scale comparable to the diameter of the solitonic core. The scaling symmetry of the SP equation and the uncertainty principle tightly relate the core mass to the halo specific energy, which, in the context of cosmological structure formation, leads to a simple scaling between core mass (Mc) and haloh , where a is the cosmic scale factor. We verify this scaling relation by (i) examining the internal structure of a statistical sample of virialized halos that form in our 3D cosmological simulations, and by (ii) merging multiple solitons to create individual virialized objects. Sufficient simulation resolution is achieved by adaptive mesh refinement and graphic processing units acceleration. From this scaling relation, present dwarf satellite galaxies are predicted to have kpc sized cores and a minimum mass of ∼ 10 8 M⊙, capable of solving the small-scale controversies in the cold dark matter model. Moreover, galaxies of 2 × 10 12 M⊙ at z = 8 should have massive solitonic cores of ∼ 2 × 10 9 M⊙ within ∼ 60 pc. Such cores can provide a favorable local environment for funneling the gas that leads to the prompt formation of early stellar spheroids and quasars.PACS numbers: 03.75. Lm, 95.35.+d, 98.56.Wm, 98.62.Gq Accumulating evidences suggest that the Universe contains ∼ 26% dark matter [1] which interacts primarily through self-gravity. Dark matter comprising very light bosons with a mass m ψ ∼ 10 −22 eV has been recognized as a viable means of suppressing low mass galaxies and providing cored profiles in dark matter dominated galaxies [2,3]. Interestingly, this boson mass scale can naturally arise in a non-QCD axion model [4], lending support for the very light boson. The relative deficiency of the observed number of low-mass galaxies is a major problem for standard cold dark matter (CDM) [5][6][7], for which a steeply rising mass function is predicted [8]. Furthermore, the dwarf spheroidal galaxies [9-20] and low surface brightness galaxies [21,22] are generally inferred to have large flat cores of dark matter, at odds with the singular cores required by standard CDM [23,24]. Complicated baryonic physics such as supernova feedback is required to solve both issues in the CDM paradigm [25][26][27][28][29][30][31][32][33][34].Extremely light bosonic dark matter can be assumed to be non-thermally generated and described by a single coherent wave function [2,[35][36][37][38], which we term ψDM. Here solutions to both the missing-satellite and ...

A bosonic dark matter model is examined in detail via high-resolution simulations. These bosons have particle mass of order 10 −22 eV and are non-interacting. If they do exist and can account for structure formation, these bosons must be condensed into the Bose-Einstein state and described by a coherent wave function. This matter, also known as Fuzzy Dark Matter (Hu, Barkana & Gruzinov 2000), is speculated to be able, first, to eliminate the sub-galactic halos to solve the problem of over-abundance of dwarf galaxies, and, second, to produce flat halo cores in galaxies suggested by some observations. We investigate this model with simulations up to 1024 3 resolution in an 1 h −1 Mpc box that maintains the background matter density Ω m = 0.3 and Ω Λ = 0.7. Our results show that the extremely light bosonic dark matter (ELBDM) can indeed eliminate low-mass halos through the suppression of short-wavelength fluctuations, as predicted by the linear perturbation theory. But to the contrary of expectation, our simulations yield singular cores in the collapsed halos, where the halo density profile is similar, but not identical, to the NFW profile (Navarro, Frenk & White 1997). Such a profile arises regardless of whether the halo forms through accretion or merger. In addition, the virialized halos exhibit anisotropic turbulence inside a well-defined virial boundary. Much like the velocity dispersion of standard dark matter particles, turbulence is dominated by the random radial flow in most part of the halos and becomes isotropic toward the halo cores. Consequently the three-dimensional collapsed halo mass distribution can deviate from spherical symmetry, as the cold dark matter halo does.

Wave dark matter (ψDM) predicts a compact soliton core and a granular halo in every galaxy. This work presents the first simulation study of an elliptical galaxy by including both stars and ψDM, focusing on the systematic changes of the central soliton and halo granules. With the addition of stars in the inner halo, we find the soliton core consistently becomes more prominent by absorbing mass from the host halo than that without stars, and the halo granules become "non-isothermal", "hotter" in the inner halo and "cooler" in the outer halo, as opposed to the isothermal halo in pure ψDM cosmological simulations. Moreover, the composite (star+ψDM) mass density is found to follow a r −2 isothermal profile near the half-light radius in most cases. Most striking is the velocity dispersion of halo stars that increases rapidly toward the galactic center by a factor of at least 2 inside the half-light radius caused by the deepened soliton gravitational potential, a result that compares favorably with observations of elliptical galaxies and bulges in spiral galaxies. However in some rare situations we find a phase segregation turning a compact distribution of stars into two distinct populations with high and very low velocity dispersions; while the highvelocity component mostly resides in the halo, the very low-velocity component is bound to the interior of the soliton core, resembling stars in faint dwarf spheroidal galaxies.

Mounting evidence from x-ray observations reveals that bound objects should receive some form of energy in the past injected from non-gravitaional sources. We report that an instantaneous heating scheme, for which gases in dense regions were subjected to a temperature jump of 1keV at z = 2 whereas those in rarified regions remained intact, can produce bound objects obeying the observed mass-temperature and luminosity-temperature relations. Such preheating lowers the peak Sunyaev-Zeldovich (SZ) power by a factor of 2 and exacerbates the need for the normalization of matter fluctuations σ 8 to assume an extreme high value (∼ 1.1) for the SZ signals to account for the excess anisotropy on 5-arcminute scale detected by the Cosmic Background Imager in the cosmic microwave background radiation.Subject headings: cosmology: theory -cosmic microwave background -intergalactic medium

Quantum turbulence that exhibits vortex creation, annihilation and interactions is demonstrated as an exact solution of the time-dependent, free-particle Schrödinger equation evolved from a smooth random-phased initial condition. Relaxed quantum turbulence in 2D and 3D exhibits universal scaling in the steady-state energy spectrum as k −1 in small scales. Due to the lack of dissipation, no evidence of the Kolmogorov-type forward energy cascade in 3D or the inverse energy cascade in 2D is found, but the rotational and potential flow components do approach equi-partition in the scaling regime. In addition, the 3D vortex line-line correlation exhibits universal behaviour, scaled as r −2 , where r is the separation between any two vortex line elements, in fully developed turbulence. We also show that the quantum vortex is not frozen to the matter, nor is the vortex motion induced by other vortices via Biot-Savart's law. Thus, the quantum vortex is actually a nonlinear wave, propagating at a speed very different from a classical vortex.

We use a scanning gate microscopy to perturb coherent transport in chemical vapor deposition (CVD) graphene wide constriction. Particularly, we observe conductance oscillations in the wide constriction region (W ∼ 800 nm) characterized by spatial conductance variations, which imply formation of the nanometer-scale ring structure due to the merged domains and intrinsic grain boundaries. Moreover, additional hot charges from high current can suppress the coherent transport, suggesting that the hot carriers with a wide spreading kinetic energy could easily tunnel merged domains and intrinsic grain boundaries in CVD-grown graphene due to the heating effect, a great advantage for applications in graphene-based interference-type nano-electronics.

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Multi-layer graphene has many unique properties for realizing graphene-based nano-electronic device applications as well as for fundamental studies. This paper mainly focuses on the conductance fluctuations in multi-layer graphene. The low-temperature saturation of dephasing time in multi-layer graphene is one order magnitude shorter than that in single-layer graphene, and the onset temperature of the low-temperature saturation of dephasing time in multi-layer graphene was significantly lower than that in single-layer graphene, which is noteworthy in the low-temperature saturation of dephasing time. We speculate that the carrier transport is shielded by capping transport and bottom layer graphene due to the substrate impurities and air molecules scattering.