13846702
Planck 2013 results. X. HFI energetic particle effects: Characterization, removal, and simulation
This paper presents the detection, interpretation and removal of the signal resulting from interactions of high energy particles with the Planck High Frequency Instrument (HFI). These interactions fall into two categories, heating the 0.1 K bolometer plate and glitches in each detector time stream. Glitch shapes are not simple single pole exponential decays and fall into a three families. The glitch shape for each family has been characterized empirically in flight data and removed from the detector time streams. The spectrum of the count rate/unit energy is computed for each family and a correspondence to where on the detector the particle hit is made. Most of the detected glitches are from galactic protons incident on the Si die frame supporting the micromachined bolometric detectors. At HFI, the particle flux is ~ 5 per square cm and per second and is dominated by protons incident on the spacecraft with an energy >39 MeV, leading to a rate of typically one event per second and per detector. Different categories of glitches have different signature in timestreams. Two of the glitch types have a low amplitude component that decays over nearly 1 second. This component produces an excess noise if not properly removed from the time ordered data. We have used a glitch detection and subtraction method based on the joint fit of population templates. The application of this novel glitch removal method removes excess noise from glitches. Using realistic simulations, we find this method does not introduce signal bias.
119468667
Gravitational Waves Probe the Coalescence Rate of Massive Black Hole Binaries
We calculate the expected nHz-μHz gravitational wave (GW) spectrum from coalescing massive black hole (MBH) binaries resulting from mergers of their host galaxies. We consider detection of this spectrum by precision pulsar timing and a future pulsar timing array. The spectrum depends on the merger rate of massive galaxies, the demographics of MBHs at low and high redshift, and the dynamics of MBH binaries. We apply recent theoretical and observational work on all of these fronts. The spectrum has a characteristic strain hc(f) ~ 10-15(f/yr-1)-2/3, just below the detection limit from recent analysis of precision pulsar timing measurements. However, the amplitude of the spectrum is still very uncertain owing to approximations in the theoretical formulation of the model, to our lack of knowledge of the merger rate and MBH population at high redshift, and to the dynamical problem of removing enough angular momentum from the MBH binary to reach a GW-dominated regime.
17460509
Simultaneous Estimation of Noise and Signal in Cosmic Microwave Background Experiments
To correctly analyse data sets from current microwave detection technology, one is forced to estimate the sky signal and experimental noise simultaneously. Given a time-ordered data set we propose a formalism and method for estimating the signal and associated errors without prior knowledge of the noise power spectrum. We derive the method using a Bayesian formalism and relate it to the standard methods; in particular we show how this leads to a change in the estimate of the noise covariance matrix of the sky signal. We study the convergence and accuracy of the method on two mock observational strategies and discuss its application to a currently-favoured calibration procedure.
15621530
Constraining large–scale structure theories with the cosmic background radiation
The case is strong that cosmic microwave background (CMB) and large scale structure (LSS) observations can be combined to determine the theory of structure formation and the cosmological parameters that define it. We review: the relevant (10+) parameters associated with the inflation model of fluctuation generation and the matter content of the universe; the relation between LSS and primary and secondary CMB anisotropy probes as a function of wavenumber; how COBE constraints on energy injection rule out explosions as a dominant source of LSS; and how current anisotropy band–powers in multipole–space, at levels ca. 10−5)2, strongly support the gravitational instability theory and suggest the universe could not have reionized too early. We use Bayesian analysis methods to determine what current CMB and CMB+LSS data imply for inflation–based Gaussian fluctuations in tilted &Lgr;CDM, &Lgr;hCDM and oCDM model sequences with cosmological age 11 – 15 Gyr, consisting of mixtures of baryons, cold ‘c’ (and possibly hot ‘h’) dark matter, vacuum energy &Lgr;, and curvature energy ‘o’ in open cosmologies. For example, we find the slope of the initial spectrum is within about 5% of the (preferred) scale–invariant form when just the CMB data are used, and for &Lgr;CDM when LSS data are combined with CMB; with both, a non–zero value of Ω&Lgr; is strongly preferred (ca. ⅔ for a 13 Gyr sequence, similar to the value from SNIa). The oCDM sequence prefers Ωtot < 1, but is overall much less likely than the flat Ω&Lgr; ≠ 0 sequence with CMB+LSS. We also review the rosy forecasts of angular power spectra and parameter estimates from future balloon and satellite experiments when foreground and systematic effects are ignored to show where cosmic parameter determination can go with CMB information alone.
119408227
CMB likelihood functions for beginners and experts
Although the broad outlines of the appropriate pipeline for cosmological likelihood analysis with CMB data has been known for several years, only recently have we had to contend with the full, large-scale, computationally challenging problem involving both highly-correlated noise and extremely large datasets (N>1000). In this talk we concentrate on the beginning and end of this process. First, we discuss estimating the noise covariance from the data itself in a rigorous and unbiased way; this is essentially an iterated minimum-variance mapmaking approach. We also discuss the unbiased determination of cosmological parameters from estimates of the power spectrum or experimental bandpowers.
122687802
Imaging the early universe with the BOOMERanG Experiment
The BOOMERanG experiment has recently detected temperature fluctuations the Cosmic Microwave Background (CMB), the otherwise isotropic radiation coming from the early Universe. These anisotropies have a low contrast (about 30 ppm) and feature a peculiar angular power spectrum at angles corresponding to sub-horizon scales at recombination. In the current cosmological model, these structures result from acoustic oscillations in the primeval plasma. In the framework of the Hot Big Bang theory with the inflationary hypothesis, the statistical properties of the image of the CMB allow us to measure most of the cosmological parameters.
124867759
The Particle Structure of the Weakly Coupled P(φ)2 Model and Other Applications of High Temperature Expansions: Part I. Physics of Quantum Field Models
35704824
The particle search in a quantum field model
The goal of quantum field theory is a description of elementary particles. When successful, this description should be both a mathematical theory and a law of nature. In our approach, we emphasize the construction of specific field theory models. The first motive for this emphasis is the mathematical consistency of quantum field theory. In addition, we follow closely the formal ideas of physics in order to provide a more solid foundation for the main task of quantum field theory: the study of elementary particles. It is clear by now that the first motive has been attained in two spacetime dimensions. In two space-time dimensions, quantum fields with nonlinear interactions have been constructed [1], [2]. For the polynomial boson (^(0)2) interactions with small coupling constant, all the Wightman axioms have been verified [5]. We announce two new results. The first is an estimate which is a major technical step toward establishing the above results in three space-time dimensions. The second result concerns the physical interpretation of our two dimensional models (the second motive of our study). In ( )2 models with a small coupling constant, we establish the existence of particles and we verify the Haag-Ruelle axioms for scattering. Thus we conclude that the ^((/>)2 model has the qualitative structure required for the description of (many particle) scattering experiments. In our first result we consider the $3 interaction: a $ 4 coupling in the interaction Hamiltonian for boson fields in three space-time dimensions. We introduce a space cut-off g e CQ(R), 0 ^ 0 ^ 1, in the interaction Hamiltonian density, and we let the resulting total Hamiltonian (with infinite counterterms from second and third order perturbation theory) be denoted H(g). Let A(g) denote the set of points within distance 1 of supp g.
120239182
Quantum Field Theory Models
Quantum fields are believed to provide a correct description of the interactions between particles. In the case of quantum electrodynamics, calculations based on perturbation theory provide exact agreement between theory and experiment within the limits of experimental accuracy. These calculations rely on infinite renormalizations and therefore reveal that quantum fields are highly singular. In these lectures, we will be concerned with the qualitative structure of quantum fields. Given a classical Lagrangian, we seek a mathematically complete construction of the corresponding quantum fields. Because of the difficulty of this problem, we have restricted ourselves to two space time dimensions. With this restriction, the program has been successful. Quantum fields have been constructed for the o2n and Yukawa interactions in two dimensions. Many properties of the fields have been verified for these models, and the o2n theory obeys all the Haag-Kastler axioms. Two major unanswered questions are: 
 
a) 
 
Can the existence of local quantum fields be extended to three space time dimensions? 
 
 
 
 
b) 
 
For the two dimensional models, can detailed properties of the fields be established in order to describe elementary particles and their bound states? Is standard perturbation theory asymptotic to the exact solution of the models? Do standard dispersion relations hold for the cross sections?
117402928
Vortices and Monopoles: Structure of Static Gauge Theories
118568324
Classical Gauge Theories and Their Quantum Role
The classical Euclidean variational equations (δA= 0, where A is the action functional, play two important roles. First, in dimension d ≤ 3 they provide time independent solutions to classical four-dimensional physics. In that way, for example, the Ginzburg-Landau model has proved important in the theory of superconductivity. The second role of Euclidean stationary points of the action is to provide a starting point for classical approximations to quantum fields. We make some remarks on these two topics; for classical gauge theories we restrict attention to the Higgs model.