An SIDM Solution to the Extreme Diversity of Low-mass Halo Properties

The properties of low-mass dark matter halos appear to be remarkably diverse relative to predictions of cold, collisionless dark matter, even in the presence of baryons. We show that self-interacting dark matter can simultaneously explain two extreme measurements of halo diversity in different directions -- namely, the rotation curves of low-concentration halos associated with gas-rich ultra-diffuse galaxies in the field and the inner density profile of the dense substructure perturbing the strong lens galaxy SDSSJ0946+1006. We present the first cosmological zoom-in simulation featuring strong dark matter self-interactions in a galaxy group environment centered on a $10^{13}~M_{\mathrm{\odot}}$ host halo. These interactions produce kiloparsec-scale cores in low-concentration isolated halos, which could host the ultra-diffuse galaxies, while most surviving subhalos of the group-mass host are deeply core-collapsed, yielding excellent candidates for the observed dense strong-lens perturber. Our scenario can be further tested with observations of galactic systems over a wide mass range.Comment: 10 pages, 6 figure

Strong Dark Matter Self-interactions Diversify Halo Populations Within and Surrounding the Milky Way

We perform a high-resolution cosmological zoom-in simulation of a Milky Way (MW)-like system, which includes a realistic Large Magellanic Cloud analog, using a large differential elastic dark matter self-interaction cross section that reaches $\approx 100~\mathrm{cm}^2\ \mathrm{g}^{-1}$ at relative velocities of $\approx 10~\mathrm{km\ s}^{-1}$, motivated by observational features of dwarf galaxies within and surrounding the MW. We explore the effects of dark matter self-interactions on satellite, splashback, and isolated halos through their abundance, central densities, maximum circular velocities, orbital parameters, and correlations between these variables. We use an effective constant cross section model to analytically predict the stages of our simulated halos' gravothermal evolution, demonstrating that deviations from the collisionless $R_{\rm max}$--$V_{\rm max}$ relation can be used to select deeply core-collapsed halos, where $V_{\rm max}$ is a halo's maximum circular velocity and $R_{\rm max}$ is the radius at which it occurs. We predict that a sizable fraction ($\approx 20\%$) of subhalos with masses down to $\approx 10^8~M_{\odot}$ are deeply core-collapsed in our SIDM model. Core-collapsed systems form $\approx 10\%$ of the total isolated halo population down to the same mass; these isolated, core-collapsed halos would host faint dwarf galaxies in the field with extremely steep central density profiles reminiscent of the Tucana dwarf galaxy. Finally, most halos with masses above $\approx 10^9~M_{\odot}$ are core-forming in our simulation. Our study thus demonstrates how self-interactions diversify halo populations in an environmentally-dependent fashion within and surrounding MW-mass hosts, providing a compelling avenue to address the diverse dark matter distributions of observed dwarf galaxies.Comment: 28 pages, 17 figure

A Parametric Model for Self-Interacting Dark Matter Halos

We propose a parametric model for studying self-interacting dark matter (SIDM) halos. The model uses an analytical density profile, calibrated using a controlled N-body SIDM simulation that covers the entire gravothermal evolution, including core-forming and -collapsing phases. By normalizing the calibrated density profile, we obtain a universal description for SIDM halos at any evolution phase. The model allows us to infer properties of SIDM halos based on their cold dark matter (CDM) counterparts. As a basic application, we only require two characteristic parameters of an isolated CDM halo at $z=0$. We then extend the model to incorporate effects induced by halo mass changes, such as major mergers or tidal stripping, making it applicable to both isolated halos and subhalos. The parametric model is tested and validated using cosmological zoom-in SIDM simulations available in the literature.Comment: 22 pages, 14 figures, typos fixed, add an appendix for the model based on the CORE-NFW ("Read") profile; example scripts provided through a lin

Dark Periods in Rabi Oscillations of Superconducting Phase Qubit Coupled to a Microscopic Two-Level System

We proposed a scheme to demonstrate macroscopic quantum jumps in a superconducting phase qubit coupled to a microscopic two-level system in the Josephson tunnel junction. Irradiated with suitable microwaves, the Rabi oscillations of the qubit exhibit signatures of quantum jumps: a random telegraph signal with long intervals of intense macroscopic quantum tunneling events (bright periods) interrupted by the complete absence of tunneling events (dark periods). An analytical model was developed to describe the width of the dark periods quantitatively. The numerical simulations indicate that our analytical model captured underlying physics of the system. Besides calibrating the quality of the microscopic two-level system, our results have significance in quantum information process since dark periods in Rabi oscillations are also responsible for errors in quantum computing with superconducting qubits.Comment: 9 pages, 8 figure

Anisotropic transport for ν=2/5\nu=2/5 FQH state at intermediate magnetic field

The $\nu=2/5$ state is spin-unpolarized at weak magnetic field and fully polarized at strong field. At intermediate field, a plateau of half the maximal polarization is observed. We study this phenomenon in the frame of composite fermion theory. Due to the mixing of the composite fermion Landau levels, the unidirectional charge/spin density wave state of composite fermions is lower in energy than the Wigner crystal. It means that transport anisotropy, similar to those for electrons in higher Landau levels at half fillings, may take place at this fractional quantum Hall state when the external magnetic field is in an appropriate range. When the magnetic field is tilted an angle, the easy transport direction is perpendicular to the direction of the in-plane field. Varying the partial filling factor of composite fermion Landau level from 0 to 1, we find that the energy minimum occurs in the vicinity of one-half.Comment: 2 figure

A new metric for rotating charged Gauss-Bonnet black holes in AdS spaces

This paper presents a new metric for slowly rotating charged Gauss-Bonnet black holes in higher dimensional anti-de Sitter spaces. Taking the angular momentum parameter $a$ up to second order, the slowly rotating charged black hole solutions are obtained by working directly in the action.Comment: 11 pages and accepted by Chin. Phys.

Spin operator matrix elements in the quantum Ising chain: fermion approach

Using some modification of the standard fermion technique we derive factorized formula for spin operator matrix elements (form-factors) between general eigenstates of the Hamiltonian of quantum Ising chain in a transverse field of finite length. The derivation is based on the approach recently used to derive factorized formula for Z_N-spin operator matrix elements between ground eigenstates of the Hamiltonian of the Z_N-symmetric superintegrable chiral Potts quantum chain. The obtained factorized formulas for the matrix elements of Ising chain coincide with the corresponding expressions obtained by the Separation of Variables Method.Comment: 19 page

Determinant representations of scalar products for the open XXZ chain with non-diagonal boundary terms

With the help of the F-basis provided by the Drinfeld twist or factorizing F-matrix for the open XXZ spin chain with non-diagonal boundary terms, we obtain the determinant representations of the scalar products of Bethe states of the model.Comment: Latex file, 28 pages, based on the talk given by W. -L. Yang at Statphys 24, Cairns, Australia, 19-23 July, 201

Haemophilus influenzae type b and Streptococcus pneumoniae as causes of pneumonia among children in Beijing, China.

To determine if Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae could be identified more often from the nasopharynx of patients with pneumonia than from control patients, we obtained nasopharyngeal swab specimens from 96 patients with chest x-ray-confirmed pneumonia and 214 age-matched control patients with diarrhea or dermatitis from the outpatient department at Beijing Children's Hospital. Pneumonia patients were more likely to be colonized with Hib and S. pneumoniae than control patients, even after the data were adjusted for possible confounding factors such as day-care attendance, the presence of other children in the household, and recent antibiotic use. In China, where blood cultures from pneumonia patients are rarely positive, the results of these nasopharyngeal cultures provide supporting evidence for the role of Hib and S. pneumoniae as causes of childhood pneumonia

New Spinor Field Realizations of the Non-Critical W3W_{3} String

We investigate the new spinor field realizations of the $W_{3}$ algebra, making use of the fact that the $W_{3}$ algebra can be linearized by the addition of a spin-1 current. We then use these new realizations to build the nilpotent Becchi-Rouet-Stora--Tyutin (BRST) charges of the spinor non-critical $W_{3}$ string.Comment: 8 pages, no figures, revtex4 style, accepted by Chin. Phys. Let