THE APM CLUSTER SURVEY: CLUSTER DETECTION AND LARGE-SCALE STRUCTURE

The APM Cluster Survey was based on a modification of Abell's original classification scheme for galaxy clusters. Here we discuss the results of an investigation of the stability of the statistical properties of the cluster catalogue to changes in the selection parameters. For a poor choice of selection parameters we find clear indications of line-of-sight clusters, but there is a wide range of input parameters for which the statistical properties of the catalogue are stable. We conclude that clusters selected in this way are indeed useful as tracers of large-scale structure.Comment: to appear in Proceedings of the XXXth Moriond Conference. 4 pages, gzipped, uuencoded postscript (inc. 2 figures

The CGLMP Bell Inequalities and Quantum Theory

Quantum non-locality tests have been of interest since the original EPR paper. The present paper discusses whether the CGLMP (Bell) inequalities obtained by Collins et al are possible tests for showing that quantum theory is not underpinned by local hidden variable theory (LHVT). It is found by applying Fine's theorem that the CGLMP approach involves a LHVT for the probabilities associated with measurements on two observables (each from one of the two sub-subsystems), even though the underlying probabilities for measurements of all four observables involve a hidden variable theory which is not required to be local. Although the CGLMP inequalities involve probabilities for measurements of one observable per sub-system and are compatible with the Heisenberg uncertainty principle, there is no unambiguous quantum measurement process linked to the probabilities in the CGLMP inequalities. Quantum measurements corresponding to the different classical measurements that give the same CGLMP probability are found to yield different CGLMP probabilities. However, violation of a CGLMP inequality based on any one of the possible quantum measurement sequences is sufficient to show that the Collins et al LHVT does not predict the same results as quantum theory. This is found to occur for a state considered in their paper - though for observables whose physical interpretation is unclear. In spite of the problems of comparing the HVT inequalities with quantum expressions, it is concluded that the CGLMP inequalities are indeed suitable for ruling out local hidden variable theories. The state involved could apply to a macroscopic system, so the CGLMP Bell inequalities are important for finding cases of macroscopic violations of Bell locality. Possible experiments in double-well Bose condensates involving atoms with two hyperfine components are discussed.Comment: 23 pages, 0 figures. Version 4. Significant revision of previous version. Relation of CGLMP inequalities to local hidden variable theories demonstrated via Fine's theore

Theory of decoherence in Bose-Einstein condensate interferometry

A full treatment of decoherence and dephasing effects in BEC interferometry has been developed based on using quantum correlation functions for treating interferometric effects. The BEC is described via a phase space distribution functional of the Wigner type for the condensate modes and the positive P type for the non-condensate modes. Ito equations for stochastic condensate and non-condensate field functions replace the functional Fokker-Planck equation for the distribution functional and stochastic averages of field function products determine the quantum correlation functions.Comment: Proceedings DICE 06 Conference, 11-15 Sept 2006, Piombino, Ital

Theory of decoherence in Bose-Einstein condensate interferometry

A full treatment of decoherence and dephasing effects in BEC interferometry has been developed based on using quantum correlation functions for treating interferometric effects. The BEC is described via a phase space distribution functional of the Wigner type for the condensate modes and the positive P type for the non-condensate modes. Ito equations for stochastic condensate and non-condensate field functions replace the functional Fokker-Planck equation for the distribution functional and stochastic averages of field function products determine the quantum correlation functions.Comment: Proceedings DICE 06 Conference, 11-15 Sept 2006, Piombino, Ital

Theory of decoherence in Bose-Einstein condensate interferometry

A full treatment of decoherence and dephasing effects in BEC interferometry has been developed based on using quantum correlation functions for treating interferometric effects. The BEC is described via a phase space distribution functional of the Wigner type for the condensate modes and the positive P type for the non-condensate modes. Ito equations for stochastic condensate and non-condensate field functions replace the functional Fokker-Planck equation for the distribution functional and stochastic averages of field function products determine the quantum correlation functions.Comment: Proceedings DICE 06 Conference, 11-15 Sept 2006, Piombino, Ital

Cascade atom in high-Q cavity: The spectrum for non-Markovian decay

The spontaneous emission spectrum for a three level cascade configuration atom in a single mode high-Q cavity coupled to a zero temperature reservoir of continuum external modes is determined from the atom-cavity mode master equation using the quantum regression theorem. Initially the atom is in its upper state and the cavity mode empty of photons. Following Glauber, the spectrum is defined via the response of a detector atom. Spectra are calculated for the detector located inside the cavity (case A), outside the cavity end mirror (Case B-end emission), or placed for emission out the side of the cavity (Case C). The spectra for case A and case B are found to be essentially the same. In all the cases the predicted lineshapes are free of instrumental effects and only due to cavity decay. Spectra are presented for intermediate and strong coupling regime situations (where both atomic transitions are resonant with the cavity frequency), for cases of non-zero cavity detuning, and for cases where the two atomic transition frequencies differ. The spectral features for Cases B(A) and C are qualitatively similar, with six spectral peaks for resonance cases and eight for detuned cases. These general features of the spectra can be understood via the dressed atom model. However, Case B and C spectra differ in detail, with the latter exhibiting a deep spectral hole at the cavity frequency due to quantum interference effects.Comment: 29 pages, 14 figures; v2: very minor correction to two equations, thicker lines in some figure

On the CCD Calibration of Zwicky galaxy magnitudes & The Properties of Nearby Field Galaxies

We present CCD photometry for galaxies around 204 bright (m_Z < 15.5) Zwicky galaxies in the equatorial extension of the APM Galaxy Survey, sampling and area over 400 square degrees, which extends 6 hours in right ascension. We fit a best linear relation between the Zwicky magnitude system, m_Z, and the CCD photometry, B, by doing a likehood analysis that corrects for Malmquist bias. This fit yields a mean scale error in Zwicky of 0.38 mag per magnitude: ie Delta m_Z = (0.62 \pm 0.05) Delta B and a mean zero point of = -0.35 \pm 0.15 mag. The scatter around this fit is about 0.4 mag. Correcting the Zwicky magnitude system with the best fit model results in a 60% lower normalization and 0.35 mag brighter M_* in the luminosity function. This brings the CfA2 luminosity function closer to the other low redshift estimations (eg Stromlo-APM or LCRS). We find a significant positive angular correlation of magnitudes and position in the sky at scales smaller than about 5 armin, which corresponds to a mean separation of 120 Kpc/h. We also present colours, sizes and ellipticities for galaxies in our fields which provides a good local reference for the studies of galaxy evolution.Comment: Full size figures can be found in http://www.ieec.fcr.es/cosmo-www/zwicky.ps Version accepted for publication in MNRAS. Extended discussion on properties of nearby galaxies. References added. An inconsistency in the R band isophote used has been corrected. Main results and conclusions are unchange

Introduction: Catherine Malabou, plasticity and film

Notes Towards a Malabouian Film-Philosophy: Introduction to the "Catherine Malabou, Plasticity and Film" Special Issue of Film-Philosophy, offering extended reflections on the possibilities of engagement between the philosophy of Catherine Malabou and the field of Film Studies

Field Quantization, Photons and Non-Hermitean Modes

Field quantization in three dimensional unstable optical systems is treated by expanding the vector potential in terms of non-Hermitean (Fox-Li) modes in both the cavity and external regions. The cavity non-Hermitean modes (NHM) are treated using the paraxial and monochromaticity approximations. The NHM bi-orthogonality relationships are used in a standard canonical quantization procedure based on introducing generalised coordinates and momenta for the electromagnetic (EM) field. The quantum EM field is equivalent to a set of quantum harmonic oscillators (QHO), associated with either the cavity or the external region NHM. This confirms the validity of the photon model in unstable optical systems, though the annihilation and creation operators for each QHO are not Hermitean adjoints. The quantum Hamiltonian for the EM field is the sum of non-commuting cavity and external region contributions, each of which is sum of independent QHO Hamiltonians for each NHM, but the external field Hamiltonian also includes a coupling term responsible for external NHM photon exchange processes. Cavity energy gain and loss processes is associated with the non-commutativity of cavity and external region operators, given in terms of surface integrals involving cavity and external region NHM functions on the cavity-external region boundary. The spontaneous decay of a two-level atom inside an unstable cavity is treated using the essential states approach and the rotating wave approximation. Atomic transitions leading to cavity NHM photon absorption have a different coupling constant to those leading to photon emission, a feature resulting from the use of NHM functions. Under certain conditions the decay rate is enhanced by the Petermann factor.Comment: 38 pages, tex, 2 figures, ps. General expression for decay rate added. To be published in Journal of Modern Optic