A theory for studying the dynamic scaling properties of branes and relativistic topological defect networks is presented. The theory, based on a relativistic version of the level set method, well known in other contexts, possesses self-similar “scaling” solutions, for which one can calculate many quantities of interest. Here, the length and area densities of cosmic strings and domain walls are calculated in Minkowski space, and radiation, matter, and curvature-dominated Friedmann-Robertson-Walker cosmologies with two and three space dimensions. The scaling exponents agree with the naive ones based on dimensional analysis, except for cosmic strings in three-dimensional Minkowski space, which are predicted to have a logarithmic correction to the naive scaling form. The scaling amplitudes of the length and area densities are a factor of approximately 2 lower than the results from numerical simulations of classical field theories. An expression for the length density of strings in the condensed matter literature is corrected.

By combining the technologies of ion trapping and cavity QED, we have achieved deterministic coupling of single ions to an optical field. By Doppler cooling, the spread of the ion's wavepacket was reduced to 42 nm, corresponding to Lamb-Dicke localization. As an application, we have measured the three-dimensional structure of cavity eigenmodes with sub-wavelength precision. The setup presented is suited for the controlled coherent processing of atomic and photonic quantum information. Examples include the triggered generation of single photons and two-ion quantum gates.

We present in this paper a detailed analysis of the effect of environment on the star formation activity of galaxies within the Early Data Release (EDR) of the Sloan Digital Sky Survey (SDSS). We have used the Halpha emission line to derive the star formation rate (SFR) for each galaxy within a volume-limited sample of 8598 galaxies with 0.05 less than or equal to z less than or equal to 0.095 and M (r*) less than or equal to 20.45. We find that the SFR of galaxies is strongly correlated with the local ( projected) galaxy density, and thus we present here a density-SFR relation that is analogous to the density-morphology relation. The effect of density on the SFR of galaxies is seen in three ways. First, the overall distribution of SFRs is shifted to lower values in dense environments compared with the field population. Second, the effect is most noticeable for the strongly star-forming galaxies (Halpha EW > 5 Angstrom) in the 75th percentile of the SFR distribution. Third, there is a break ( or characteristic density) in the density-SFR relation at a local galaxy density of similar to1 h(75)(-2) Mpc(-2). To understand this break further, we have studied the SFR of galaxies as a function of clustercentric radius from 17 clusters and groups objectively selected from the SDSS EDR data. The distribution of SFRs of cluster galaxies begins to change, compared with the field population, at a clustercentric radius of 3-4 virial radii (at the >1sigma statistical significance), which is consistent with the characteristic break in density that we observe in the density-SFR relation. This effect with clustercentric radius is again most noticeable for the most strongly star-forming galaxies. Our tests suggest that the density-morphology relation alone is unlikely to explain the density-SFR relation we observe. For example, we have used the ( inverse) concentration index of SDSS galaxies to classify late-type galaxies and show that the distribution of the star-forming (EW Halpha > 5Angstrom) late-type galaxies is different in dense regions ( within 2 virial radii) compared with similar galaxies in the field. However, at present, we are unable to make definitive statements about the independence of the density-morphology and density-SFR relation. We have tested our work against potential systematic uncertainties including stellar absorption, reddening, SDSS survey strategy, SDSS analysis pipelines, and aperture bias. Our observations are in qualitative agreement with recent simulations of hierarchical galaxy formation that predict a decrease in the SFR of galaxies within the virial radius. Our results are in agreement with recent 2dF Galaxy Redshift Survey results as well as consistent with previous observations of a decrease in the SFR of galaxies in the cores of distant clusters. Taken together, these works demonstrate that the decrease in SFR of galaxies in dense environments is a universal phenomenon over a wide range in density (from 0.08 to 10 h(75)(-2) Mpc(-2)) and redshift (out to z similar or equal to 0.5).

The ATLAS experiment at CERN forms a big challenge in detector development, due to its size and expected data rate provided by the Large Hadron Collider, which is expected to be operational in 2007. The Semi-Conductor Tracker will use silicon strip sensors and is one of the three inner tracking detectors foreseen for the ATLAS experiment, which will be enclosed in a 2 T solenoid magnetic field. Its main goal is to provide four precision measurements of each charged particle's track. This paper focuses on the silicon strip detector modules used in the forward direction of the experiment, which are about to go into production. The two endcap detector systems that will be constructed will consist of approximately 13 m2 sensor surface with over 3 million channels in about 2000 detector modules. This paper describes the design of the detector modules and shows the results on their performance.

The SIRTF Wide-Area Infrared Extragalactic Survey (SWIRE), the largest SIRTF Legacy program, is a wide-area imaging survey to trace the evolution of dusty, star-forming galaxies, evolved stellar populations, and active galactic nuclei (AGNs) as a function of environment, from redshifts to the current z ∼ 3 epoch. SWIRE will survey seven high-latitude fields, totaling 60–65 deg2 in all seven SIRTF bands: Infrared Array Camera (IRAC) 3.6, 4.5, 5.6, and 8 mm and Multiband Imaging Photometer for SIRTF (MIPS) 24, 70, and 160 mm. Extensive modeling suggests that the Legacy Extragalactic Catalog may contain in excess of 2 million IR-selected galaxies, dominated by (1) ∼150,000 luminous infrared galaxies (LIRGs; LFIR 1 1011 L,) detected by MIPS (and significantly more detected by IRAC), ∼7000 of these with ; (2) 1 million IRAC- z 1 2 detected early-type galaxies (∼ with and ∼10,000 with ); and (3) ∼20,000 classical AGNs 5 2 # 10 z 1 1 z 1 2 detected with MIPS, plus significantly more dust-obscured quasi-stellar objects/AGNs among the LIRGs. SWIRE will provide an unprecedented view of the evolution of galaxies, structure, and AGNs.

The key scientific goals of SWIRE are (1) to determine the evolution of actively star forming and passively evolving galaxies in order to understand the history of galaxy formation in the context of cosmic structure formation; (2) to determine the evolution of the spatial distribution and clustering of evolved galaxies, starbursts, and AGNs in the key redshift range over which much of cosmic evolution has occurred; and (3) to 0.5 ! z ! 3 determine the evolutionary relationship between “normal galaxies” and AGNs and the contribution of AGN accretion energy versus stellar nucleosynthesis to the cosmic backgrounds. The large area of SWIRE is important to establish statistically significant population samples over enough volume cells that we can resolve the star formation history as a function of epoch and environment, i.e., in the context of structure formation. The large volume is also optimized for finding rare objects.

The SWIRE fields are likely to become the next generation of large “cosmic windows” into the extragalactic sky. They have been uniquely selected to minimize Galactic cirrus emission over large scales. The Galaxy Evolution Explorer will observe them as part of its deep 100 deg2 survey, as will Herschel. SWIRE includes ∼9 deg2 of the unique large-area XMM Large Scale Structure hard X-ray imaging survey and is partly covered by the UKIDSS deep J and K survey. An extensive optical/near-IR imaging program is underway from the ground. The SWIRE data are nonproprietary; catalogs and images will be released twice yearly, beginning about 11 months after SIRTF launch. Details of the data products and release schedule are presented.

The sources discovered in deep hard X-ray surveys with 2–8 keV fluxes of S2−8 ∼ 10−14 erg cm−2 s−1 make up the bulk of the X-ray background at these energies. Here we present detailed multiwavelength observations of three such sources from the European Large-Area ISO Survey Deep X-ray Survey. The observations include sensitive near-infrared spectroscopy with the Subaru Telescope and X-ray spectral information from the Chandra X-ray Observatory. The sources observed all have optical-to-near-infrared (near-IR) colours redder than an unobscured quasar and comprise a reddened quasar, a radio galaxy and an optically obscured active galactic nucleus (AGN). The reddened quasar is at a redshift z = 2.61 and shows a very large X-ray absorbing column of NH ≈ 3 × 1023 cm−2. This contrasts with the relatively small amount of dust reddening, implying a gas-to-dust ratio along the line of sight 100 times greater than that of the Milky Way. The radio galaxy at z = 1.57 shows only narrow emission lines, but has a surprisingly soft X-ray spectrum. The softness of this spectrum indicates either an unusually low gas-to-dust ratio for the absorbing medium or X-ray emission related to the young radio source. The host galaxy is extremely red (R − K = 6.4) and its optical/near-IR spectrum is best fit by a strongly reddened (AV ≈ 2) starburst. The third X-ray source discussed is also extremely red (R − K = 6.1) and lies in a close grouping of three other R − K > 6 galaxies. No emission or absorption lines were detected from this object, but its redshift (and that of one of the nearby galaxies) is constrained by spectral energy distribution fitting to be just greater than z = 1. The extremely red colours of these two galaxies can be accounted for by old stellar populations. These observations illustrate the diverse properties of hard X-ray-selected AGN at high redshift in terms of obscuration at optical and X-ray wavelengths and the evolutionary states of their host galaxies.

The widely discussed applications in quantum information and quantum cryptography require radiation sources capable of producing a fixed number of photons. This paper reviews the work performed in our laboratory to produce these fields on demand. Two different methods are discussed. The first is based on the one-atom maser or micromaser operating under the conditions of the so-called trapping states. In this situation the micromaser stabilises to a photon number state. Recently, we also succeeded in determining the Wigner function of a single-photon state. The second device, recently realized in our laboratory, uses a single trapped ion in an optical cavity.

We present a toy model for five-dimensional heterotic M-theory where bulk three-branes, originating in 11 dimensions from M five-branes, are modelled as kink solutions of a bulk scalar field theory. It is shown that the vacua of this defect model correspond to a class of topologically distinct M-theory compactifications. Topology change can then be analysed by studying the time evolution of the defect model. In the context of a four-dimensional effective theory, we study in detail the simplest such process, that is the time evolution of a kink and its collision with a boundary. We find that the kink is generically absorbed by the boundary thereby changing the boundary charge. This opens up the possibility of exploring the relation between more complicated defect configurations and the topology of brane-world models.

The European Large Area ISO Survey (ELAIS) was the largest single Open Time project conducted by ISO, mapping an area of 12 square degrees at 15μm with ISO-CAM and at 90μ with ISOPHOT. We first present the data analysis of the 90 μm survey. We show comparisons with model prediction for standard stars and with COBE/DIRBE for surface brightnesses of individual ELAIS fields and with the IRAS FSC catalog for 35 sources in common. The large number of rasters necessary to cover the wide ELAIS areas allows to compute a relative uncertainty for the calibration based on the FCS of typically 7%. From the comparison with standard stars model predictions, the absolute calibration is shown to be better than 15%.

The survey is 1.5 order of magnitude deeper than the IRAS 100μ m survey and is expected to provide constraints on the formation and evolution of galaxies.

Finally, we present 90 μm number counts from a reliable subset of the detected sources. ELAIS number counts are compared to the evolutionnary models of Guiderdoni (1998) and Rowan-Robinson (2001).

Cold atoms in optical potentials provide an ideal test bed to explore quantum nonlinear dynamics. Atoms are prepared in a magneto-optic trap or as a dilute Bose-Einstein condensate and subjected to a far detuned optical standing wave that is modulated. They exhibit a wide range of dynamics, some of which can be explained by classical theory while other aspects show the underlying quantum nature of the system. The atoms have a mixed phase space containing regions of regular motion which appear as distinct peaks in the atomic momentum distribution embedded in a sea of chaos. The action of the atoms is of the order of Planck's constant, making quantum effects significant. This tutorial presents a detailed description of experiments measuring the evolution of atoms in time-dependent optical potentials. Experimental methods are developed providing means for the observation and selective loading of regions of regular motion. The dependence of the atomic dynamics on the system parameters is explored and distinct changes in the atomic momentum distribution are observed which are explained by the applicable quantum and classical theory. The observation of a bifurcation sequence is reported and explained using classical perturbation theory. Experimental methods for the accurate control of the momentum of an ensemble of atoms are developed. They use phase space resonances and chaotic transients providing novel ensemble atomic beamsplitters. The divergence between quantum and classical nonlinear dynamics is manifest in the experimental observation of dynamical tunnelling. It involves no potential barrier. However a constant of motion other than energy still forbids classically this quantum allowed motion. Atoms coherently tunnel back and forth between their initial state of oscillatory motion and the state 180° out of phase with the initial state.

We study the evolution of domain wall networks appearing after phase transitions in the early Universe. They exhibit interesting dynamical scaling behavior which is not yet well understood, and are also simple models for the more phenomenologically acceptable string networks. We have run numerical simulations in two- and three-dimensional lattices of sizes up to 4096^3. The theoretically predicted scaling solution for the wall area density A1/t is supported by the simulation results, while no evidence of a logarithmic correction reported in previous studies could be found. The energy loss mechanism appears to be direct radiation, rather than the formation and collapse of closed loops or spheres. We discuss the implications for the evolution of string networks.

We constrain slow-roll inflationary models using the recent Wilkinson Microwave Anisotropy Probe data combined with data from the VSA, CBI, ACBAR and 2dF experiments. We find the slow-roll parameters to be 0<epsilon(1)<0.032 and epsilon(2)+5.0epsilon(1)=0.036+/-0.025. For inflation models Vproportional tophi(alpha) we find that alpha<3.9,4.3 at the 2sigma and 3sigma levels, indicating that the lambdaphi(4) model is under very strong pressure from observations. We define a convergence criterion to judge the necessity of introducing further power spectrum parameters such as the spectral index and running of the spectral index. This criterion is typically violated by models with large negative running that fit the data, indicating that the running cannot be reliably measured with present data.

Temperature maps are presented of the nine largest clusters in the mock catalogues of Muanwong et al. for both the Preheating and Radiative models. The maps show that clusters are not smooth, featureless systems, but contain a variety of substructure which should be observable. The surface brightness contours are generally elliptical and features that are seen include cold clumps, hot spiral features and cold fronts. Profiles of emission-weighted temperature, surface brightness, density and pressure across the surface brightness discontinuities seen in one of the bimodal clusters are consistent with the cold front in Abell 2142 observed by Markevitch et al.

The dynamics of a three-level atom in a cascade (or ladder) configuration with both transitions coupled to a single structured reservoir of quantized electromagnetic field modes is treated using Laplace transform methods applied to the coupled amplitude equations. In this system two-photon excitation of the reservoir occurs, and both sequences for emitting the two photons are allowed and included in the theory. An integral equation is found to govern the complex amplitudes of interest. It is shown that the dynamics of the atomic system is completely determined in terms of reservoir structure functions, which are products of the mode density with the coupling constant squared. This dependence on reservoir structure functions rather than on the mode density or coupling constants alone, shows that it may be possible to extend pseudomode theory to treat multiphoton excitation of a structured reservoirb

We present the results of a large library of cosmological N-body simulations, using power-law initial spectra. The non-linear evolution of the matter power spectra is compared with the predictions of existing analytic scaling formulae based on the work of Hamilton et al. The scaling approach has assumed that highly non-linear structures obey ‘stable clustering’ and are frozen in proper coordinates. Our results show that, when transformed under the self-similarity scaling, the scale-free spectra define a non-linear locus that is clearly shallower than would be required under stable clustering. Furthermore, the small-scale non-linear power increases as both the power spectrum index n and the density parameter Ω decrease, and this evolution is not well accounted for by the previous scaling formulae. This breakdown of stable clustering can be understood as resulting from the modification of dark matter haloes by continuing mergers. These effects are naturally included in the analytic ‘halo model’ for non-linear structure; we use this approach to fit both our scale-free results and also our previous cold dark matter data. This method is more accurate than the commonly used Peacock–Dodds formula and should be applicable to more general power spectra.

The paper analyzes the interaction of an atomic system with a quantum damped harmonic oscillator. Such an oscillator is the building block in the recently proposed models of bulk dielectrics and may also serve as a simple model of a small dielectric body. Dispersion and losses are taken into account by assuming the oscillator to be coupled to a zero-temperature reservoir consisting of an infinite system of other harmonic oscillators. The Greens function of the atomic system is calculated perturbatively when coupled to the bath. The self-energy of the atomic electron is obtained by the partial resummation of perturbation diagrams, and thus energy-level shifts of both ground and excited states of the atom due to the presence of the oscillator are determined. Corrections to the decay rates are also obtained and analyzed as functions of the distance of the atom from the oscillator, and of the coupling of the oscillator to the reservoir.

The energy-level shift of a ground-state atom in front of a nondispersive dielectric half-space is calculated by quantizing the electric field by means of a normal-mode expansion and applying second-order perturbation theory to the electric-dipole Hamiltonian muE. It is shown that the contributions to this shift coming from traveling and from evanescent waves can be combined into a single expression which lends itself readily to asymptotic analysis for large atom-surface separations, while in the opposite asymptotic regime when the atom is close to the surface the combined expression is less convenient. Employing a Greens-function formalism instead of the normal-mode expansion leads directly to the combined formula, and in that case it is advantageous to be able to apply the same transformation backwards and split the energy shift into a sum of distinct contributions corresponding to different physical processes. The analysis serves to shed light on common sources of error in the literature and paves the way for the study of more complicated models in cavity quantum electrodynamics.

Using hydrodynamical simulations of the Λ-cold dark matter cosmology that include both radiative cooling and a phenomenological model for star formation and supernovae feedback, we investigate the impact of galaxy formation on the X-ray properties of groups at zero redshift. Motivated by the observed ‘break’ in the Lx–Tx relation at kTx∼ 1–2 keV, our feedback model is based on the assumption that supernovae imprint a temperature scale on the hot gas, with the star formation rate and corresponding reheated gas mass then depending only on the available energy budget. We demonstrate that a strong feedback model with a heating temperature comparable to this break (kTSN= 2 keV), and an energy budget twice that available from supernovae (ε= 2), raises the core entropy of groups sufficiently to produce an adequate match to their observed X-ray properties. A lower value of ε increases the star formation rate without significantly affecting the X-ray properties of groups, and a model with ε∼ 0.1 reproduces the observed fraction of baryons in stars. However, a heating temperature that is lower than the virial temperatures of the groups leads to an excess of cooling gas that boosts their X-ray luminosities, due to the failure of the reheated material to escape from the gravitational potential. A limited study of numerical resolution effects reveals that the temperature of poorly resolved objects is underestimated, therefore (in our case) a fully resolved group population would lead to a steeper Lx–Tx relation, bringing our results into even better agreement with the observations.

Intense pulses of light can be used to guide a molecular system into particular molecular states even when the Franck-Condon overlap is very small. The process of APLIP (Adiabatic Passage by Light Induced Potentials) is an example where light induced potentials effect the change of electronic state whilst maintaining the vibrational state. In this paper we look at the robustness of APLIP to some of its controlling parameters.

We present results from the European Large Area ISO Survey (ELAIS) at 90 micron. With about 11.6 deg2 the survey is the largest area covered by ISO in a single programme and is 1.5 order of magnitude deeper than the IRAS 100 micron survey. Differential number counts are presented and show an excess of a factor up to 3.5 above the no-evolution model prediction at the faintest end of the survey. This confirms the strong evolution detected at shorter(15 micron) and longer (170 micron) wavelength in other ISO surveys. Comparison with several recent evolutionary models show that the best agreement with the observations is found for the model of Guiderdoni et al. (2001) which incorporates a heavily-extinguished population of galaxies.

Reconstructing the shape of the primordial power spectrum in a model-independent way from cosmological data is a useful consistency check on what is usually assumed regarding early universe physics. It is also our primary window to unknown physics during the inflationary era. Using a power-law form for the primordial power spectrum Pin(k) and constraining the scalar spectral index and its running, in 2003 Peiris and coworkers found that the first-year Wilkinson Microwave Anistropy Probe (WMAP) data seem to indicate a preferred scale in Pin(k). We use two complementary methods, the wavelet band power method of Mukherjee & Wang and the top-hat binning method of Wang, Spergel, & Strauss, to reconstruct Pin(k) as a free function from cosmic microwave background (CMB) data alone (WMAP, CBI, and ACBAR), or from CMB data together with large-scale structure data (2dFGRS and PCSz). The shape of the reconstructed Pin(k) is consistent with scale invariance, although it allows some indication of a preferred scale at k~0.01 Mpc-1. While consistent with the possible evidence for a running of the scalar spectral index found by the WMAP team, our results highlight the need of more stringent and independent constraints on cosmological parameters (the Hubble constant in particular) in order to more definitively constrain deviations of Pin(k) from scale invariance without making assumptions about the inflationary model.

The neutral B meson lifetime is measured with the data collected by the BABAR detector at the PEP-II storage ring during the years 1999 and 2000, with a total integrated luminosity of 20.7 fb(-1). The decays B-0 --> D*- pi(+) and B-0 --> D*- rho(+) are selected with a partial-reconstruction technique, yielding samples of 6970 6240 and 55206250 signal events, respectively. With these events, the B-0 lifetime is measured to be 1.533 +/-0.034 (stat) +/-0.038 (syst) ps. This measurement serves as a test and validation of procedures required to measure the CP violation parameter sin(2beta+gamma) with partial reconstruction of these modes.

We use the block model to generate merger trees for the first star clusters in a Λ-cold dark matter cosmology. Using a simple collapse model and cooling criterion, we determine which haloes are able to form stars before being disrupted by mergers. We contrast the mass functions of all the resulting star clusters and those of primordial composition, i.e. star clusters that have not been contaminated by subclusters inside them. In confirmation of previous work, two generations of primordial star clusters are identified: low-temperature clusters that cool via molecular hydrogen, and high-temperature clusters that cool via electronic transitions. The former dominate by number, but the two populations contain a similar mass with the precise balance depending upon the details of the model. We speculate on the current-day distribution of Population III stars.

As part of a combined Sunyaev-Zeldovich Effect (SZE), X-ray and weak lensing survey of low redshift (z<0.1) X-ray clusters, we present SZE images of the z=0.059 X-ray cluster Abell 3266 at three observing frequencies (150, 220, 275 GHz) and after the spectral subtraction of primary Cosmic Microwave Background (CMB) anisotropies. These images were generated using the ACBAR bolometer array operated on the Viper telescope at the South Pole. The multi-frequency data from ACBAR should allow us to overcome one of the main obstacles facing the analysis of SZE observations of nearby clusters, i.e. contamination from primary Cosmic Microwave Background (CMB) anisotropies.

We present a spectroscopic analysis of a sample of 21 galaxies with z = 0.2-1.5 drawn from a 25 square arcmin ultra-deep ISOCAM survey at lambdaeff =15 mu m centered in the WFPC-2 Hubble Deep Field South. Near-infrared spectra are reported for 18 ISO sources, carried out with ISAAC on the VLT, aimed at detecting the redshifted Halpha +[NII]. Additional optical data come from the ESO VLT/FORS2 and NTT/EMMI, primarily targeting [OII], [OIII] and Hbeta for further physical insight. Although not numerous in terms of areal density in the sky, this population of very luminous IR sources has been recently found to be responsible for a substantial fraction of the extragalactic background light energy density. Halpha line emission is detected in virtually all the observed objects down to a flux limit of 7 x 10-17 erg cm-2 s-1 (corresponding to LH_alpha > 1041 erg s-1 at z = 0.6 for H0 = 65, OmegaLambda=0.7 and Omegam = 0.3). Our analysis (including emission line, morphology, and SED properties) shows clear evidence for AGN activity in only two of these sources: one type-I (with broadened Halpha at z=1.57) and one type-II quasars (with inverted [NII]/Halpha ratio at z=1.39), while we suspect the presence of an AGN in two further sources (an Ultra-Luminous IR Galaxy, ULIRG, at z=1.27 and a luminous galaxy at z=0.69). The Halpha luminosities indicate star formation rates (SFR) in the remaining sources between 0.5 and 20 Msun/yr, assuming a Salpeter IMF between 0.1 and 100 Msun and without extinction corrections. We find good correlations between the mid-IR, the radio and Halpha luminosities, confirming the mid-IR light as a good tracer of star formation (while the SFR based on Halpha flux show some large scatter and offset, which are still to be understood). We have estimated the baryonic masses in stars with a newly-developed tool fitting the overall optical-IR continuum, and found that the host galaxies of ISO sources are massive members of groups with typically high rates of SF (SFR ~ 10 to 300 Msun/yr). We have finally compared this ongoing SF activity with the already formed stellar masses to estimate the timescales tSF for the stellar build-up, which turn-out to be widely spread in these objects between 0.1 Gyrs to more than 10 Gyr. The faint ISOCAM galaxies appear to form a composite population, including moderately active but very massive spiral-like galaxies, and very luminous ongoing starbursts, in a continuous sequence. From the observed tSF and assuming typical starburst timescales, we infer that, with few exceptions, only a fraction of the galactic stars can be formed in any single starburst event, while several of such episodes during a protracted SF history are required for the whole galactic build-up.

The amplitude of density perturbations, for the currently-favoured CDM cosmology, is constrained using the observed properties of galaxy clusters. The catalogue used is that of Ikebe et al. The relation of cluster temperature to mass is obtained via N-body/hydrodynamical simulations including radiative cooling and pre-heating of cluster gas, which we have previously shown to reproduce well the observed temperature–mass relation in the innermost parts of clusters. We generate and compare mock catalogues via a Monte Carlo method, which allows us to constrain the relation between X-ray temperature and luminosity, including its scatter, simultaneously with cosmological parameters. We find a luminosity–temperature relation in good agreement with the results of Ikebe et al., while for the matter power spectrum normalization, we find σ8 = 0.78+0.30 −0.06 at 95 per cent confidence for 0 = 0.35. Scaling to the Wilkinson Microwave Anisotropy Probe central value of 0 = 0.27 would give a best-fitting value of σ8 ≃ 0.9.

We have employed radio-frequency trapping to localize a single 40Ca+-ion in a high-finesse optical cavity. By means of laser Doppler cooling, the position spread of the ion's wavefunction along the cavity axis was reduced to 42 nm, a fraction of the resonance wavelength of ionized calcium (λ = 397 nm). By controlling the position of the ion in the optical field, continuous and completely deterministic coupling of ion and field was realized. The precise three-dimensional location of the ion in the cavity was measured by observing the fluorescent light emitted upon excitation in the cavity field. The single-ion system is ideally suited to implement cavity quantum electrodynamics under cw conditions. To this end we operate the cavity on the D3/2–P1/2 transition of 40Ca+ (λ = 866 nm). Applications include the controlled generation of single-photon pulses with high efficiency and two-ion quantum gates.

Extra dimensions have interesting consequences for flavor physics. We consider a setup where the standard model fermions and gauge fields reside in the bulk of a warped extra dimension. Fermion masses and mixings are explained by flavor dependent fermion locations, without relying on hierarchical Yukawa couplings. We discuss various flavor violating processes induced by (Kaluza–Klein) gauge boson exchange and non-renormalizable operators. Experimental constraints are satisfied with a Kaluza–Klein scale of about 10 TeV. Some processes, such as muon–electron conversion, are within reach of next generation experiments.

A microscopic Ioffe–Pritchard trap is formed using a straight, current-carrying wire, together with suitable auxiliary magnetic fields. By measuring the distribution of cold rubidium atoms held in this trap, we detect a weak magnetic field component ΔBz parallel to the wire. This is produced by the current in the wire and is approximately periodic along the wire with period λ = 230 µm. We have measured this field at distances in the range y = 250–350 µm from the centre of the wire. Over this range we find that the decrease of the field is well described by the Bessel function K1(2πy/λ), as one would expect for the far field of a transversely oscillating current within the wire.