Identifying A New Intermediate Polar Using Xmm-Newton And Integral,
2012
University of Durham
Identifying A New Intermediate Polar Using Xmm-Newton And Integral, Matthew J. Middleton, Edward M. Cackett, Craig Shaw, Gavin Ramsay, Timothy P. Roberts, Peter J. Wheatley
Physics and Astronomy Faculty Research Publications
The bright X-ray source 2XMMi J180438.7-145647 is fortunate to have long baseline observations in INTEGRAL that complement observations taken by other missions. Optical spectroscopy of this object has suggested a distance of ˜7 kpc and an identification with a low-mass X-ray binary. We instead use the X-ray data from 0.3 to 40 keV to identify the source as a bright intermediate polar (IP) with an estimate for the white dwarf mass of ˜0.60 M⊙. This identification is supported by the presence of an iron triplet, the component lines of which are some of the strongest seen in IPs, …
Essentials Of The Theory Of Abstraction - Lecture,
2012
SelectedWorks
Essentials Of The Theory Of Abstraction - Lecture, Subhajit Kumar Ganguly
Subhajit Kumar Ganguly
In not favouring solutions or sets of solutions, the principle of zero-postulation drives away any unwanted incompleteness from the description of the world. It is the interactions between the possible exhaustive set of solutions that creates the impression pointedness or directiveness in the universe, leading to the formation of clusters, as discussed earlier. These interactions may be chaotic in nature, giving rise to attractor points where the directiveness inside any given system asymptotically seem to approach. It is this directiveness, in turn, inside a given system or in the universe as a whole, that is the cause of all known …
Topspin Networks In Loop Quantum Gravity,
2012
Merrimack
Topspin Networks In Loop Quantum Gravity, Christopher L. Duston
Physics Faculty Publications
We discuss the extension of loop quantum gravity to topspin networks, a proposal which allows topological information to be encoded in spin networks. We will show that this requires minimal changes to the phase space, C*-algebra and Hilbert space of cylindrical functions. We will also discuss the area and Hamiltonian operators, and show how they depend on the topology. This extends the idea of 'background independence' in loop quantum gravity to include topology as well as geometry. It is hoped this work will confirm the usefulness of the topspin network formalism and open up several new avenues for research into …
Interacting Dark Energy Models And The Cosmic Coincidence Problem,
2012
Arkansas Tech University
Interacting Dark Energy Models And The Cosmic Coincidence Problem, H. Shojaei, C. Smith, D. Waters
Journal of the Arkansas Academy of Science
Interacting dark energy models have been employed to study the behavior of dark energy and matter in the presence of an interaction between the two. One of the successful aspects of these models is how they explain the cosmic coincidence problem. In this work we consider a specific interaction to study the behavior of dark energy and matter through the history of evolution.
Everything Is Entangled,
2012
Chapman University
Everything Is Entangled, Roman V. Buniy, Stephen D. H. Hsu
Mathematics, Physics, and Computer Science Faculty Articles and Research
We show that big bang cosmology implies a high degree of entanglement of particles in the universe. In fact, a typical particle is entangled with many particles far outside our horizon. However, the entanglement is spread nearly uniformly so that two randomly chosen particles are unlikely to be directly entangled with each other - the reduced density matrix describing any pair is likely to be separable.
Toward Solving The Cosmological Constant Problem By Embedding,
2012
Chapman University
Toward Solving The Cosmological Constant Problem By Embedding, Roman V. Buniy, Thomas W. Kephart
Mathematics, Physics, and Computer Science Faculty Articles and Research
The typical scalar field theory has a cosmological constant problem. We propose a generic mechanism by which this problem is avoided at tree level by embedding the theory into a larger theory. The metric and the scalar field coupling constants in the original theory do not need to be fine-tuned, while the extra scalar field parameters and the metric associated with the extended theory are fine-tuned dynamically. Hence, no fine-tuning of parameters in the full Lagrangian is needed for the vacuum energy in the new physical system to vanish at tree level. The cosmological constant problem can be solved if …
Isometries And Spontaneous Lorentz Violation In General Relativity,
2012
Colby College
Isometries And Spontaneous Lorentz Violation In General Relativity, Greg Merritt
Honors Theses
General Relativity, or GR, is a theory which describes gravity as a manifestation of the curvature of space and time. While the other three fundamental forces in nature are represented as field theories, GR is a geometric theory. In the search for a way to reconcile the field theories for the electromagnetic, strong, and weak forces with the gravitational force, a logical place to start is by re-expressing GR as a field theory. In doing so, we find that the theory contains a number of symmetries. When we solve the equations in GR, we find that by choosing certain solutions …
Quantization And Discretization At Large Scales,
2012
University of New Mexico
Quantization And Discretization At Large Scales, Florentin Smarandache, Victor Christianto, Pavel Pintr
Branch Mathematics and Statistics Faculty and Staff Publications
The ongoing search of extrasolar planets is one of the most attractive fields of research in astrophysics and astronomy. Up to now, 360 extrasolar planets have been discovered near stars with similar mass as the Sun. There is also discovery related to the so-called Earth-like planets. With regards to these discoveries, one intriguing question is whether there is relationship between orbit distance of the planets and their stars. Various formulas have been suggested since 1990s, and they suggest that there may be reason to accept quantization of distances of those planets both in our solar system and also in extrasolar …
Vacuum, Space-Time, Matter And The Models Of Smarandache Geometry,
2012
University of New Mexico
Vacuum, Space-Time, Matter And The Models Of Smarandache Geometry, Florentin Smarandache, Hu Chang-Wei
Branch Mathematics and Statistics Faculty and Staff Publications
Many fundamental concepts in physics remain unsolved: What is time? Is it pure relative? What is the vacuum? Is it void space or special medium? What is mass? Can it be created? I believe that physicists have not got definite answers for the above questions. Isaac Newton said: I was like a boy playing on the sea-shore, and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me. For instance, we still do not know what the clear definition of time …
Derivation Of The Binary Mass Function,
2011
Utah State University
Derivation Of The Binary Mass Function, Eric Addison
Eric Addison
The observational quantity f(m), the binary mass function, is derived.
Correlation Of Inflation-Produced Magnetic Fields With Scalar Fluctuations,
2011
Dartmouth College
Correlation Of Inflation-Produced Magnetic Fields With Scalar Fluctuations, Robert R. Caldwell, Leonardo Motta, Marc Kamionkowski
Dartmouth Scholarship
If the conformal invariance of electromagnetism is broken during inflation, then primordial magnetic fields may be produced. If this symmetry breaking is generated by the coupling between electromagnetism and a scalar field—e.g. the inflaton, curvaton, or Ricci scalar—then these magnetic fields may be correlated with primordial density perturbations, opening a new window to the study of non-Gaussianity in cosmology. In order to illustrate, we couple electromagnetism to an auxiliary scalar field in a de Sitter background. We calculate the power spectra for scalar-field perturbations and magnetic fields, showing how a scale-free magnetic-field spectrum with rms amplitude of ∼nG at Mpc …
The Hubble Space Telescope * Cluster Supernova Survey. Ii. The Type Ia Supernova Rate In High-Redshift Galaxy Clusters,
2011
University of San Francisco
The Hubble Space Telescope * Cluster Supernova Survey. Ii. The Type Ia Supernova Rate In High-Redshift Galaxy Clusters, K Barbary, G Aldering, R Amanullah, M Brodwin, N Connolly, Ks Dawson, M Doi, P Eisenhardt, L Faccioli, V Fadeyev, Hk Fakhouri, As Fruchter, D G. Gilbank, Md Gladders, G Goldhaber, A Goobar, T Hattori, E Hsiao, Xiaosheng Huang, Y Ihara, K Kashikawa, B Koester, K Konishi, M Kowalski, C Lidman, L Lubin, J Meyers, T Morokuma, T Oda, N Panagia, S Perlmutter, M Postman, P Ripoche, P Rosati, D Rubin, Dj Schlegel, Al Spadafora, Sa Stanford, M Strovink, N Suzuki, N Takanashi, K Tokita, N Yasuda
Physics and Astronomy
We report a measurement of the Type Ia supernova (SN Ia) rate in galaxy clusters at 0.9 < z < 1.46 from the Hubble Space Telescope Cluster Supernova Survey. This is the first cluster SN Ia rate measurement with detected z > 0.9 SNe. Finding 8 ± 1 cluster SNe Ia, we determine an SN Ia rate of 0.50+0.23 –0.19 (stat) +0.10 –0.09 (sys) h 2 70 SNuB (SNuB ≡ 10–12 SNe L –1 ☉, B yr–1). In units of stellar mass, this translates to 0.36+0.16 –0.13 (stat) +0.07 –0.06 (sys) h 2 70 SNuM (SNuM ≡ 10–12 SNe M –1 ☉ yr–1). This represents a …
Nikhef
Application Of Asymptotic Expansions For Maximum Likelihood Estimators' Errors To Gravitational Waves From Inspiraling Binary Systems: The Network Case, Salvatore Vitale, Michele Zanolin
Publications
This paper describes the most accurate analytical frequentist assessment to date of the uncertainties in the estimation of physical parameters from gravitational waves generated by nonspinning binary systems and Earth-based networks of laser interferometers. The paper quantifies how the accuracy in estimating the intrinsic parameters mostly depends on the network signal to noise ratio (SNR), but the resolution in the direction of arrival also strongly depends on the network geometry. We compare results for 6 different existing and possible global networks and two different choices of the parameter space. We show how the fraction of the sky where the one …
Holographic Renormalization Of Asymptotically Lifshitz Spacetimes,
2011
Loyola University Chicago
Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, Robert A. Mcnees Iv, Robert Mann
Physics: Faculty Publications and Other Works
A variational formulation is given for a theory of gravity coupled to a massive vector in four dimensions, with Asymptotically Lifshitz boundary conditions on the fields. For theories with critical exponent z=2 we obtain a well-defined variational principle by explicitly constructing two actions with local boundary counterterms. As part of our analysis we obtain solutions of these theories on a neighborhood of spatial infinity, study the asymptotic symmetries, and consider different definitions of the boundary stress tensor and associated charges. A constraint on the boundary data for the fields figures prominently in one of our formulations, and in that case …
Holographic Renormalization Of Asymptotically Lifshitz Spacetimes,
2011
Loyola University Chicago
Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, Robert Mcnees, Robert Mann
Robert A McNees IV
A variational formulation is given for a theory of gravity coupled to a massive vector in four dimensions, with Asymptotically Lifshitz boundary conditions on the fields. For theories with critical exponent z = 2 we obtain a well-defined variational principle by explicitly constructing two actions with local boundary counterterms. As part of our analysis we obtain solutions of these theories on a neighborhood of spatial infinity, study the asymptotic symmetries, and consider different definitions of the boundary stress tensor and associated charges. A constraint on the boundary data for the fields figures prominently in one of our formulations, and in …
Veritas Observations Of The Unusual Extragalactic Transient Swift J164449.3+573451,
2011
Department of Physical Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
Veritas Observations Of The Unusual Extragalactic Transient Swift J164449.3+573451, P. T. Reynolds, Et Al
Physical Sciences Publications
We report on very high energy (>100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the Swift Observatory and later detected by multiple radio, optical, and X-ray observatories. A total exposure of 28 hr was obtained on Swift J164449.3+573451 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) during 2011 March 28-April 15. We do not detect the source and place a differential upper limit on the emission at 500 GeV during these observations of 1.4 × 10–12 erg cm–2 s–1 (99% confidence level). We also present time-resolved upper limits and use a …
The Variable Quiescent X-Ray Emission Of The Neutron Star Transient Xte J1701-462,
2011
Massachusetts Institute of Technology
The Variable Quiescent X-Ray Emission Of The Neutron Star Transient Xte J1701-462, Joel K. Fridriksson, Jeroen Homan, Rudy Wijnands, Edward M. Cackett, Diego Altamirano, Nathalie Degenaar, Edward F. Brown, Mariano Méndez, Tomaso M. Belloni
Physics and Astronomy Faculty Research Publications
We present the results of continued monitoring of the quiescent neutron star low-mass X-ray binary XTE J1701-462 with Chandra and Swift. A new Chandra observation from 2010 October extends our tracking of the neutron star surface temperature from ≃ 800 days to ≃ 1160 days since the end of an exceptionally luminous 19 month outburst. This observation indicates that the neutron star crust may still be slowly cooling toward thermal equilibrium with the core; another observation further into quiescence is needed to verify this. The shape of the overall cooling curve is consistent with that of a broken power law, …
Quiescent X-Ray Variability From The Neutron Star Transient Aql X-1,
2011
Institute of Astronomy, University of Cambridge
Quiescent X-Ray Variability From The Neutron Star Transient Aql X-1, E. M. Cackett, J. K. Fridriksson, J. Homan, J. M. Miller, R. Wijnands
Physics and Astronomy Faculty Research Publications
A number of studies have revealed variability from neutron star low-mass X-ray binaries during quiescence. Such variability is not well characterized, or understood, but may be a common property that has been missed due to lack of multiple observations. One such source where variability has been observed is Aql X-1. Here, we analyse 14 Chandra and XMM-Newton observations of Aql X-1 in quiescence, covering a period of approximately 2 yr. There is clear variability between the epochs, with the most striking feature being a flare-like increase in the flux by a factor of 5. Spectral fitting is inconclusive as to …
High Gravitational Waveform Accuracy At Null Infinity,
2011
Marshall University
High Gravitational Waveform Accuracy At Null Infinity, Maria Babiuc-Hamilton
Physics Faculty Research
The aim of Cauchy-characteristic extraction is to provide a standardized waveform extraction tool for the numerical relativity community. The new extraction tool contains major improvements and corrections to previous versions and displays convergence. The error introduced by CCE satisfies the time domain criteria required for advanced LIGO data analysis. The importance of accurate waveforms to the gravitational wave astronomy has created an urgency for tools like CCE. The source code has been released to the public and is available as part of the Einstein Toolkit. We welcome applications to a variety of generic Cauchy codes implementing Einstein Equations of General …
Interpretation Of The Arcade 2 Absolute Sky Brightness Measurement,
2011
University of Richmond
Interpretation Of The Arcade 2 Absolute Sky Brightness Measurement, M. Seiffert, D. J. Fixsen, A. Kogut, S. M. Levin, M. Limon, P. M. Lubin, P. Mirel, Jack Singal, T. Villela, E. Wollack, C. A. Wuensche
Physics Faculty Publications
We use absolutely calibrated data between 3 and 90 GHz from the 2006 balloon flight of the ARCADE 2 instrument, along with previous measurements at other frequencies, to constrain models of extragalactic emission. Such emission is a combination of the cosmic microwave background (CMB) monopole, Galactic foreground emission, the integrated contribution of radio emission from external galaxies, any spectral distortions present in the CMB, and any other extragalactic source. After removal of estimates of foreground emission from our own Galaxy, and an estimated contribution of external galaxies, we present fits to a combination of the flat-spectrum CMB and potential spectral …
