Radial Bargmann representation for the Fock space of type B

Let $\nu_{\alpha,q}$ be the probability and orthogonality measure for the $q$-Meixner-Pollaczek orthogonal polynomials, which has appeared in \cite{BEH15} as the distribution of the $(\alpha,q)$-Gaussian process (the Gaussian process of type B) over the $(\alpha,q)$-Fock space (the Fock space of type B). The main purpose of this paper is to find the radial Bargmann representation of $\nu_{\alpha,q}$. Our main results cover not only the representation of $q$-Gaussian distribution by \cite{LM95}, but also of $q^2$-Gaussian and symmetric free Meixner distributions on $\mathbb R$. In addition, non-trivial commutation relations satisfied by $(\alpha,q)$-operators are presented.Comment: 13 pages, minor changes have been mad

Draping of Cluster Magnetic Fields over Bullets and Bubbles -- Morphology and Dynamic Effects

High-resolution X-ray observations have revealed cavities and `cold fronts' with sharp edges in temperature, density, and metallicity within galaxy clusters. Their presence poses a puzzle since these features are not expected to be hydrodynamically stable, or to remain sharp in the presence of diffusion. However, a moving core or bubble in even a very weakly magnetized plasma necessarily sweeps up enough magnetic field to build up a dynamically important sheath around the object; the layer's strength is set by a competition between `plowing up' of field and field lines slipping around the core. We show that a two-dimensional approach to the problem is quite generally not possible. In three dimensions, we show with analytic arguments and in numerical experiments, that this magnetic layer modifies the dynamics of a plunging core, greatly modifies the effects of hydrodynamic instabilities on the core, modifies the geometry of stripped material, and even slows the fall of the core through magnetic tension. We derive an expression for the maximum magnetic field strength, the thickness of the layer, and the opening angle of the magnetic wake. The morphology of the magnetic draping layer implies the suppression of thermal conduction across the layer, thus conserving strong temperature gradients over the contact surface. The intermittent amplification of the magnetic field as well as the injection of MHD turbulence in the wake of the core is identified to be due to vorticity generation within the magnetic draping layer. These results have important consequences for understanding the physical properties and the complex gasdynamical processes of the intra-cluster medium, and apply quite generally to motions through other magnetized environments, e.g., the ISM.Comment: For version of this paper with interactive 3D graphics and full-resolution figures, see http://www.cita.utoronto.ca/~ljdursi/draping/ . 19p, 26 figures, emulateapj format. Version accepted by ApJ - new references, improved figure

Adaptive Sampling Approach to the Negative Sign Problem in the Auxiliary Field Quantum Monte Carlo Method

We propose a new sampling method to calculate the ground state of interacting quantum systems. This method, which we call the adaptive sampling quantum monte carlo (ASQMC) method utilises information from the high temperature density matrix derived from the monte carlo steps. With the ASQMC method, the negative sign ratio is greatly reduced and it becomes zero in the limit $\Delta \tau$ goes to zero even without imposing any constraint such like the constraint path (CP) condition. Comparisons with numerical results obtained by using other methods are made and we find the ASQMC method gives accurate results over wide regions of physical parameters values.Comment: 8 pages, 7 figure

Quiescent Thermal Emission from the Neutron Star in Aql X-1

We report on the quiescent spectrum measured with Chandra/ACIS-S of the transient, type-I X-ray bursting neutron star Aql X-1, immediately following an accretion outburst. The neutron star radius, assuming a pure hydrogen atmosphere and hard power-law spectrum, is $R_\infty$=13.4{+5}{-4} (d/5 \kpc) km. Based on the historical outburst record of RXTE/ASM, the quiescent luminosity is consistent with that predicted by Brown, Bildsten and Rutledge from deep crustal heating, lending support to this theory for providing a minimum quiescent luminosity of transient neutron stars. While not required by the data, the hard power-law component can account for 18+/-8% of the 0.5-10 keV thermal flux. Short-timescale intensity variability during this observation is less than 15% rms (3 sigma; 0.0001-1 Hz, 0.2-8 keV). Comparison between the Chandra spectrum and three X-ray spectral observations made between Oct 1992 and Oct 1996 find all spectra consistent with a pure H atmosphere, but with temperatures ranging from 145--168 eV, spanning a factor of 1.87+/-0.21 in observed flux. The source of variability in the quiescent luminosity on long timescales (greater than years) remains a puzzle. If from accretion, then it remains to be explained why the quiescent accretion rate provides a luminosity so nearly equal to that from deep crustal heating.Comment: 15 pages, 1 figure, 2 tables; ApJ, accepte

Gluino Decay as a Probe of High Scale Supersymmetry Breaking

A supersymmetric standard model with heavier scalar supersymmetric particles has many attractive features. If the scalar mass scale is O(10 - 10^4) TeV, the standard model like Higgs boson with mass around 125 GeV, which is strongly favored by the LHC experiment, can be realized. However, in this scenario the scalar particles are too heavy to be produced at the LHC. In addition, if the scalar mass is much less than O(10^4) TeV, the lifetime of the gluino is too short to be measured. Therefore, it is hard to probe the scalar particles at a collider. However, a detailed study of the gluino decay reveals that two body decay of the gluino carries important information on the scalar scale. In this paper, we propose a test of this scenario by measuring the decay pattern of the gluino at the LHC.Comment: 29 pages, 9 figures; version published in JHE

On the nature of spectral line broadening in solar coronal dimmings

We analyze the profiles of iron emission lines observed in solar coronal dimmings associated with coronal mass ejections, using the EUV Imaging Spectrometer on board Hinode. We quantify line profile distortions with empirical coefficients (asymmetry and peakedness) that compare the fitted Gaussian to the data. We find that the apparent line broadenings reported in previous studies are likely to be caused by inhomogeneities of flow velocities along the line of sight, or at scales smaller than the resolution scale, or by velocity fluctuations during the exposure time. The increase in the amplitude of Alfv\'en waves cannot, alone, explain the observed features. A double-Gaussian fit of the line profiles shows that, both for dimmings and active region loops, one component is nearly at rest while the second component presents a larger Doppler shift than that derived from a single-Gaussian fit.Comment: 16 pages, 11 figures - Accepted for publication in Ap

First XMM-Newton Observations of the Globular Cluster M22

We have examined preliminary data of the globular cluster, M22, from the EPIC MOS detectors on board XMM-Newton. We have detected 27 X-ray sources within the centre of the field of view, 24 of which are new detections. Three sources were found within the core of the cluster. From spectral analysis of the X-ray sources, it is possible that the object at the centre of the core is a quiescent X-ray transient and those lying further out are maybe cataclysmic variables.Comment: 6 pages, 3 figures, accepted to be published in Astronomy and Astrophysic

Pseudo-axions in Little Higgs models

Little Higgs models have an enlarged global symmetry which makes the Higgs boson a pseudo-Goldstone boson. This symmetry typically contains spontaneously broken U(1) subgroups which provide light electroweak-singlet pseudoscalars. Unless such particles are absorbed as the longitudinal component of $Z'$ states, they appear as pseudoscalars in the physical spectrum at the electroweak scale. We outline their significant impact on Little Higgs phenomenology and analyze a few possible signatures at the LHC and other future colliders in detail. In particular, their presence significantly affects the physics of the new heavy quark states predicted in Little Higgs models, and inclusive production at LHC may yield impressive diphoton resonances.Comment: 28 pages, 9 figs., accepted to PRD; footnote added, typos correcte