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Full-Text Articles in Physical Sciences and Mathematics
Quantum Corrections To The Schwarzschild And Kerr Metrics, N. E. J. Bjerrum-Bohr, John Donoghue, Barry R. Holstein
Quantum Corrections To The Schwarzschild And Kerr Metrics, N. E. J. Bjerrum-Bohr, John Donoghue, Barry R. Holstein
John Donoghue
We examine the corrections to the lowest order gravitational interactions of massive particles arising from gravitational radiative corrections. We show how the masslessness of the graviton and the gravitational selfinteractions imply the presence of nonanalytic pieces ;A2q2,;q2ln2q2, etc., in the form factors of the energy-momentum tensor and that these correspond to long range modifications of the metric tensor gmn of the form G2m2/r2,G2m\/r3, etc. The former coincide with well known solutions from classical general relativity, while the latter represent new quantum mechanical effects, whose strength and form is necessitated by the low energy quantum nature of the general relativity. We …
Qcd Condensates For The Light Quark V-A Correlator, Vincenzo Cirigliano, Eugene Golowich, Kim Maltman
Qcd Condensates For The Light Quark V-A Correlator, Vincenzo Cirigliano, Eugene Golowich, Kim Maltman
Physics Department Faculty Publication Series
No abstract provided.
Threshold Electrodisintegration Of 3he, R S. Hicks, A Hotta, S Churchwell, X Jiang, Gerald Alvin Peterson, J Shaw, B Asavapibhop, M C. Berisso, P E. Bosted, K Burchesky, R A. Miskimen, S E. Rock
Threshold Electrodisintegration Of 3he, R S. Hicks, A Hotta, S Churchwell, X Jiang, Gerald Alvin Peterson, J Shaw, B Asavapibhop, M C. Berisso, P E. Bosted, K Burchesky, R A. Miskimen, S E. Rock
Gerald Alvin Peterson
Cross sections were measured for the near-threshold electrodisintegration of 3He at momentum transfer values of q=2.4, 4.4, and 4.7fm-1. From these and prior measurements the transverse and longitudinal response functions RT and RL were deduced. Comparisons are made against previously published and new nonrelativistic A=3 calculations using the best available nucleon-nucleon NN potentials. In general, for q<2fm-1 these calculations accurately predict the threshold electrodisintegration of 3He. Agreement at increasing q demands consideration of two-body terms, but discrepancies still appear at the highest momentum transfers probed, perhaps due to the neglect of relativistic dynamics, or to the underestimation of high-momentum wave-function components.
Mobility Of Taxol In Microtubule Bundles, Jennifer Ross, D. Kuchnir Fygenson
Mobility Of Taxol In Microtubule Bundles, Jennifer Ross, D. Kuchnir Fygenson
Jennifer Ross
Mobility of taxol inside microtubules was investigated using fluorescence recovery after photobleaching on flowaligned bundles. Bundles were made of microtubules with either GMPCPP or GTP at the exchangeable site on the tubulin dimer. Recovery times were sensitive to bundle thickness and packing, indicating that taxol molecules are able to move laterally through the bundle. The density of open binding sites along a microtubule was varied by controlling the concentration of taxol in solution for GMPCPP samples. With [63% sites occupied, recovery times were independent of taxol concentration and, therefore, inversely proportional to the microscopic dissociation rate, koff. It was found …
Quantum Gravitational Corrections To The Nonrelativistic Scattering Potential Of Two Masses, N. E. J. Bjerrum-Bohr, John Donoghue, Barry R. Holstein
Quantum Gravitational Corrections To The Nonrelativistic Scattering Potential Of Two Masses, N. E. J. Bjerrum-Bohr, John Donoghue, Barry R. Holstein
John Donoghue
We treat general relativity as an effective field theory, obtaining the full nonanalytic component of the scattering matrix potential to one-loop order. The lowest order vertex rules for the resulting effective field theory are presented and the one-loop diagrams which yield the leading nonrelativistic post-Newtonian and quantum corrections to the gravitational scattering amplitude to second order in G are calculated in detail. The Fourier transformed amplitudes yield a nonrelativistic potential and our result is discussed in relation to previous calculations. The definition of a potential is discussed as well and we show how the ambiguity of the potential under coordinate …
Dynamics Of Conformal Maps For A Class Of Non-Laplacian Growth Phenomena, Martin Z. Bazant, Jaehyuk Choi, Benny Davidovitch
Dynamics Of Conformal Maps For A Class Of Non-Laplacian Growth Phenomena, Martin Z. Bazant, Jaehyuk Choi, Benny Davidovitch
Benny Davidovitch
Time-dependent conformal maps are used to model a class of growth phenomena limited by coupled non-Laplacian transport processes, such as nonlinear diffusion, advection, and electro- migration. Both continuous and stochastic dynamics are described by generalizing conformal- mapping techniques for viscous fingering and diffusion-limited aggregation, respectively. A gen- eral notion of time in stochastic growth is also introduced. The theory is applied to simulations of advection-diffusion-limited aggregation in a background potential flow. A universal crossover in mor- phology is observed from diffusion-limited to advection-limited fractal patterns with an associated crossover in the growth rate, controlled by a time-dependent effective Peclet number. …
Search For Neutral Baryon Resonances Below Pion Threshold, X Jiang, R Gilman, R Ransome, P Markowitz, T H. Chang, C C. Chang, Gerald Alvin Peterson
Search For Neutral Baryon Resonances Below Pion Threshold, X Jiang, R Gilman, R Ransome, P Markowitz, T H. Chang, C C. Chang, Gerald Alvin Peterson
Gerald Alvin Peterson
The reaction p(e,e′π+)X0 was studied with two high-resolution magnetic spectrometers to search for narrow baryon resonances. A missing mass resolution of 2.0 MeV was achieved. A search for structures in the mass region of 0.97
Photoproduction Of The Ω Meson On The Proton At Large Momentum Transfer, M Battaglieri, M Brunoldi, R De Vita, B Asavapibhop, R S. Hicks, D Lawrence, R Miskimen, Gerald Alvin Peterson
Photoproduction Of The Ω Meson On The Proton At Large Momentum Transfer, M Battaglieri, M Brunoldi, R De Vita, B Asavapibhop, R S. Hicks, D Lawrence, R Miskimen, Gerald Alvin Peterson
Gerald Alvin Peterson
The differential cross section, dσ/dt, for ω meson exclusive photoproduction on the proton above the resonance region (2.6
Department Of Physics Newsletter: Spring 2003, Bob Krotkov, Tony Papirio, Gerry Peterson, Monroe Rabin, Hajime Sakai
Department Of Physics Newsletter: Spring 2003, Bob Krotkov, Tony Papirio, Gerry Peterson, Monroe Rabin, Hajime Sakai
Physics Newsletters
No abstract provided.
Spatial And Temporal Gradients In The Cosmological Constant, Jf Donoghue
Spatial And Temporal Gradients In The Cosmological Constant, Jf Donoghue
Physics Department Faculty Publication Series
It is possible that there may be differences in the fundamental physical parameters from one side of the observed universe to the other. I show that the cosmological constant is likely to be the most sensitive of the physical parameters to possible spatial (or temporal) variation, because a small variation in any of the other parameters produces a huge variation of the cosmological constant. It therefore provides a very powerful indirect evidence against spatial gradients or temporal variation in the other fundamental physical parameters, at least 40 orders of magnitude more powerful than direct experimental constraints. Moreover, a gradient may …
Quantum Gravitational Corrections To The Nonrelativistic Scattering Potential Of Two Masses, Nej Bjerrum-Bohr, Jf Donoghue, Br Holstein
Quantum Gravitational Corrections To The Nonrelativistic Scattering Potential Of Two Masses, Nej Bjerrum-Bohr, Jf Donoghue, Br Holstein
Physics Department Faculty Publication Series
We treat general relativity as an effective field theory, obtaining the full nonanalytic component of the scattering matrix potential to one-loop order. The lowest order vertex rules for the resulting effective field theory are presented and the one-loop diagrams which yield the leading nonrelativistic post-Newtonian and quantum corrections to the gravitational scattering amplitude to second order in G are calculated in detail. The Fourier transformed amplitudes yield a nonrelativistic potential and our result is discussed in relation to previous calculations. The definition of a potential is discussed as well, and we show that the ambiguity of the potential under coordinate …
Comment On “Phase Diagram Of A Disordered Boson Hubbard Model In Two Dimensions”, N Prokof’Ev, B Svistunov
Comment On “Phase Diagram Of A Disordered Boson Hubbard Model In Two Dimensions”, N Prokof’Ev, B Svistunov
Physics Department Faculty Publication Series
In a recent Letter [1] (see also [2]) the authors presented numerical evidence supporting an idea of a direct transition between the superfluid (SF) and Mott insulating (MI) phases in the disordered Bosonic system, and even studied non-trivial properties of the multicritical line where SF, MI and the Bose Glass (BG) phases meet. The results were obtained from Monte Carlo simulations of the (2+1)-dimensional classical loop-current model [3] with the lattice action S = 1 2K ÞE ~ J=0 XrƒÑ ~ J2(r, ƒÑ) . 2(ƒÊ + v(r)) ~ JƒÑ (r, ƒÑ) . (1) where r, ƒÑ are spatial and imaginary …
From Wrapped M-Branes To Calabi-Yau Black Holes And Strings, David Kastor
From Wrapped M-Branes To Calabi-Yau Black Holes And Strings, David Kastor
Physics Department Faculty Publication Series
We study a class of D = 11 BPS spacetimes that describe M-branes wrapping supersymmetric 2 and 4-cycles of Calabi-Yau 3-folds. We analyze the geometrical significance of the supersymmetry constraints and gauge field equations of motion for these spacetimes. We show that the dimensional reduction to D = 5 yields known BPS black hole and black string solutions of D = 5, N = 2 supergravity. The usual ansatz for the dimensional reduction is valid only in the linearized regime of slowly varying moduli and small gauge field strengths. Our identification of the massless D = 5 modes with D …
New Evidence For Zero-Temperature Relaxation In A Spin-Polarized Fermi Liquid, H Akimoto, D Candela, Js Xia, Wj Mullin, Ed Adams, Ns Sullivan
New Evidence For Zero-Temperature Relaxation In A Spin-Polarized Fermi Liquid, H Akimoto, D Candela, Js Xia, Wj Mullin, Ed Adams, Ns Sullivan
Physics Department Faculty Publication Series
Spin-echo experiments are reported for 3He-4He solutions under extremely high B/T conditions, B=14.75 T and T≥1.73 mK. The 3He concentration x3 was adjusted close to the value xc≈3.8% at which the spin-rotation parameter μM0 vanishes. In this way the transverse and longitudinal spin-diffusion coefficients D⊥,D∥ were measured while keeping |μM0|<1. It is found that the temperature dependence of D⊥ deviates strongly from 1/T2, with anisotropy temperature Ta=4.26-0.44+0.18 mK. This value is close to the theoretical prediction for dilute solutions and suggests that spin current relaxation remains finite as the temperature tends to zero.
Spatial Gradients In The Cosmological Constant, John Donoghue
Spatial Gradients In The Cosmological Constant, John Donoghue
John Donoghue
It is possible that there may be differences in the fundamental physical parameters from one side of the observed universe to the other. I show that the cosmological constant is likely to be the most sensitive of the physical parameters to possible spatial variation, because a small variation in any of the other parameters produces a huge variation of the cosmological constant. It therefore provides a very powerful {\em indirect} evidence against spatial gradients or temporal variation in the other fundamental physical parameters, at least 40 orders of magnitude more powerful than direct experimental constraints. Moreover, a gradient may potentially …
Bogomol'nyi, Prasad And Sommerfield Configurations In Smectics, Christian Santangelo, Randall D. Kamien
Bogomol'nyi, Prasad And Sommerfield Configurations In Smectics, Christian Santangelo, Randall D. Kamien
Christian Santangelo
It is typical in smectic liquid crystals to describe elastic deformations with a linear theory when the elastic strain is small. In smectics, certain essential nonlinearities arise from the requirement of rotational invariance. By employing the Bogomol’nyi, Prasad, and Sommerfield decomposition and relying on boundary conditions and geometric invariants, we have found a large class of exact solutions. We introduce an approximation for the deformation profile far from a spherical inclusion and find an enhanced attractive interaction at long distances due to the nonlinear elasticity, confirmed by numerical minimization.
Improved Determination Of The Electroweak Penguin Contribution To E’/E In The Chiral Limit, Vincenzo Cirigliano, John Donoghue, Eugene Golowich, Kim Maltman
Improved Determination Of The Electroweak Penguin Contribution To E’/E In The Chiral Limit, Vincenzo Cirigliano, John Donoghue, Eugene Golowich, Kim Maltman
John Donoghue
We perform a finite energy sum rule analysis of the flavor ud two-point V-A current correlator, Delta Pi (Q^2). The analysis, which is performed using both the ALEPH and OPAL databases for the V-A spectral function, Delta rho, allows us to extract the dimension six V-A OPE coefficient, a_6, which is related to the matrix element of the electroweak penguin operator, Q_8, by chiral symmetry. The result for a_6 leads directly to the improved (chiral limit) determination epsilon'/epsilon = (- 15.0 +- 2.7) 10^{-4}. Determination of higher dimension OPE contributions also allows us to perform an independent test using a …
Ground State Numerical Study Of The Three-Dimensional Random Field Ising Model, I. Dukovski, Jonathan Machta
Ground State Numerical Study Of The Three-Dimensional Random Field Ising Model, I. Dukovski, Jonathan Machta
Jonathan Machta
The random field Ising model in three dimensions with Gaussian random fields is studied at zero temperature for system sizes up to 603. For each realization of the normalized random fields, the strength of the random field, Δ and a uniform external, H is adjusted to find the finite-size critical point. The finite-size critical point is identified as the point in the H−Δ plane where three degenerate ground states have the largest discontinuities in the magnetization. The discontinuities in the magnetization and bond energy between these ground states are used to calculate the magnetization and specific heat critical exponents and …
Quantum Corrections To The Schwarzschild And Kerr Metrics, Nej Bjerrum-Bohr, Jf Donoghue, Br Holstein
Quantum Corrections To The Schwarzschild And Kerr Metrics, Nej Bjerrum-Bohr, Jf Donoghue, Br Holstein
Physics Department Faculty Publication Series
No abstract provided.
K ->Pi Pi Electroweak Penguins In The Chiral Limit, V Cirigliano, Jf Donoghue, Eugene Golowich, K Maltman
K ->Pi Pi Electroweak Penguins In The Chiral Limit, V Cirigliano, Jf Donoghue, Eugene Golowich, K Maltman
Physics Department Faculty Publication Series
We report on dispersive and finite energy sum rule analyses of the electroweak penguin matrix elements left angle bracket(ππ)2|Q7,8|K0right-pointing angle bracket in the chiral limit. We accomplish the correct perturbative matching (scale and scheme dependence) at NLO in αs, and we describe two different strategies for numerical evaluation.
Incoherent Dynamics Of Vibrating Single-Molecule Transistors, K Mccarthy,, Nikolai Prokof'ev, M Tuominen
Incoherent Dynamics Of Vibrating Single-Molecule Transistors, K Mccarthy,, Nikolai Prokof'ev, M Tuominen
Physics Department Faculty Publication Series
We study the tunneling conductance of nanoscale quantum “shuttles” in connection with a recent experiment [H. Park et al., Nature 407, 57 (2000)] in which a vibrating C60 molecule was apparently functioning as the island of a single electron transistor (SET). While our calculation starts from the same model of previous work [D. Boese and H. Schoeller, Europhys. Lett. 54, 668 (2001)] we obtain quantitatively different dynamics. Calculated I-V curves exhibit most features present in experimental data with a physically reasonable parameter set, and point to a strong dependence of the oscillator’s potential on the electrostatics of the island region. …
Bose-Einstein Condensation, Fluctuations, And Recurrence Relations In Statistical Mechanics, Wj Mullin, Jp Fernandez
Bose-Einstein Condensation, Fluctuations, And Recurrence Relations In Statistical Mechanics, Wj Mullin, Jp Fernandez
Physics Department Faculty Publication Series
We calculate certain features of Bose–Einstein condensation in the ideal gas by using recurrence relations for the partition function. The grand canonical ensemble gives inaccurate results for certain properties of the condensate that are accurately provided by the canonical ensemble. Calculations in the latter can be made tractable for finite systems by means of the recurrence relations. The ideal one-dimensional harmonic Bose gas provides a particularly simple and pedagogically useful model for which detailed results are easily derived. An analysis of the Bose system via permutation cycles yields insight into the physical meaning of the recurrence relations.
Quantum Statistics: Is There An Effective Fermion Repulsion Or Boson Attraction?, Wj Mullin, G Blaylock
Quantum Statistics: Is There An Effective Fermion Repulsion Or Boson Attraction?, Wj Mullin, G Blaylock
Physics Department Faculty Publication Series
Physicists often claim that there is an effective repulsion between fermions, implied by the Pauli principle, and a corresponding effective attraction between bosons. We examine the origins and validity of such exchange force ideas and the areas where they are highly misleading. We propose that explanations of quantum statistics should avoid the idea of an effective force completely, and replace it with more appropriate physical insights, some of which are suggested here.