7,030 research outputs found

    Symmetry Breaking in the Schr\"odinger Representation for Chern-Simons Theories

    Full text link
    This paper discusses the phenomenon of spontaneous symmetry breaking in the Schr\"odinger representation formulation of quantum field theory. The analysis is presented for three-dimensional space-time abelian gauge theories with either Maxwell, Maxwell-Chern-Simons, or pure Chern-Simons terms as the gauge field contribution to the action, each of which leads to a different form of mass generation for the gauge fields.Comment: 16pp, LaTeX , UCONN-94-

    A Gauge-Gravity Relation in the One-loop Effective Action

    Full text link
    We identify an unusual new gauge-gravity relation: the one-loop effective action for a massive spinor in 2n dimensional AdS space is expressed in terms of precisely the same function [a certain multiple gamma function] as the one-loop effective action for a massive charged scalar in 4n dimensions in a maximally symmetric background electromagnetic field [one for which the eigenvalues of F_{\mu\nu} are maximally degenerate, corresponding in 4 dimensions to a self-dual field, equivalently to a field of definite helicity], subject to the identification F^2 \Lambda, where \Lambda is the gravitational curvature. Since these effective actions generate the low energy limit of all one-loop multi-leg graviton or gauge amplitudes, this implies a nontrivial gauge-gravity relation at the non-perturbative level and at the amplitude level.Comment: 6 page

    Perturbative Analysis of Nonabelian Aharonov-Bohm Scattering

    Full text link
    We perform a perturbative analysis of the nonabelian Aharonov-Bohm problem to one loop in a field theoretic framework, and show the necessity of contact interactions for renormalizability of perturbation theory. Moreover at critical values of the contact interaction strength the theory is finite and preserves classical conformal invariance.Comment: 12 pages in LaTeX, uses epsf.sty, 5 uuencoded Postscript figures sent separately. MIT-CTP-228

    Chern-Simons matrix model: coherent states and relation to Laughlin wavefunctions

    Full text link
    Using a coherent state representation we derive many-body probability distributions and wavefunctions for the Chern-Simons matrix model proposed by Polychronakos and compare them to the Laughlin ones. We analyze two different coherent state representations, corresponding to different choices for electron coordinate bases. In both cases we find that the resulting probability distributions do not quite agree with the Laughlin ones. There is agreement on the long distance behavior, but the short distance behavior is different.Comment: 15 pages, LaTeX; one reference added, abstract and section 5 expanded, typos correcte

    Mass Spectra of N=2 Supersymmetric SU(n) Chern-Simons-Higgs Theories

    Full text link
    An algebraic method is used to work out the mass spectra and symmetry breaking patterns of general vacuum states in N=2 supersymmetric SU(n) Chern-Simons-Higgs systems with the matter fields being in the adjoint representation. The approach provides with us a natural basis for fields, which will be useful for further studies in the self-dual solutions and quantum corrections. As the vacuum states satisfy the SU(2) algebra, it is not surprising to find that their spectra are closely related to that of angular momentum addition in quantum mechanics. The analysis can be easily generalized to other classical Lie groups.Comment: 17 pages, use revte

    Two new submodels for the Modular Earth Submodel System (MESSy): New Aerosol Nucleation (NAN) and small ions (IONS) version 1.0

    Get PDF
    Abstract. Two new submodels for the Modular Earth Submodel System (MESSy) were developed. The New Aerosol Nucleation (NAN) submodel includes new parameterisations of aerosol particle formation rates published in recent years. These parameterisations include ion-induced nucleation and nucleation of pure organic species. NAN calculates the rate of new particle formation based on the aforementioned parameterisations for aerosol submodels in the ECHAM/MESSy Atmospheric Chemistry (EMAC) model. The ion pair production rate, needed to calculate the ion-induced or ion-mediated nucleation, is described using the new submodel IONS, which provides ion pair production rates for other submodels within the MESSy framework. Both new submodels were tested in EMAC simulations. These simulations showed good agreement with ground-based observations. </jats:p

    Casimir Effects in Renormalizable Quantum Field Theories

    Get PDF
    We review the framework we and our collaborators have developed for the study of one-loop quantum corrections to extended field configurations in renormalizable quantum field theories. We work in the continuum, transforming the standard Casimir sum over modes into a sum over bound states and an integral over scattering states weighted by the density of states. We express the density of states in terms of phase shifts, allowing us to extract divergences by identifying Born approximations to the phase shifts with low order Feynman diagrams. Once isolated in Feynman diagrams, the divergences are canceled against standard counterterms. Thus regulated, the Casimir sum is highly convergent and amenable to numerical computation. Our methods have numerous applications to the theory of solitons, membranes, and quantum field theories in strong external fields or subject to boundary conditions.Comment: 27 pp., 11 EPS figures, LaTeX using ijmpa1.sty; email correspondence to R.L. Jaffe ; based on talks presented by the authors at the 5th workshop `QFTEX', Leipzig, September 200

    On the QED Effective Action in Time Dependent Electric Backgrounds

    Get PDF
    We apply the resolvent technique to the computation of the QED effective action in time dependent electric field backgrounds. The effective action has both real and imaginary parts, and the imaginary part is related to the pair production probability in such a background. The resolvent technique has been applied previously to spatially inhomogeneous magnetic backgrounds, for which the effective action is real. We explain how dispersion relations connect these two cases, the magnetic case which is essentially perturbative in nature, and the electric case where the imaginary part is nonperturbative. Finally, we use a uniform semiclassical approximation to find an expression for very general time dependence for the background field. This expression is remarkably similar in form to Schwinger's classic result for the constant electric background.Comment: 27 pages, no figures; reference adde

    Self-DUal SU(3) Chern-Simons Higgs Systems

    Get PDF
    We explore self-dual Chern-Simons Higgs systems with the local SU(3)SU(3) and global U(1)U(1) symmetries where the matter field lies in the adjoint representation. We show that there are three degenerate vacua of different symmetries and study the unbroken symmetry and particle spectrum in each vacuum. We classify the self-dual configurations into three types and study their properties.Comment: Columbia Preprint CU-TP-635, 19 page

    Consistency restrictions on maximal electric field strength in QFT

    Full text link
    QFT with an external background can be considered as a consistent model only if backreaction is relatively small with respect to the background. To find the corresponding consistency restrictions on an external electric field and its duration in QED and QCD, we analyze the mean energy density of quantized fields for an arbitrary constant electric field E, acting during a large but finite time T. Using the corresponding asymptotics with respect to the dimensionless parameter eET2eET^2, one can see that the leading contributions to the energy are due to the creation of paticles by the electric field. Assuming that these contributions are small in comparison with the energy density of the electric background, we establish the above-mentioned restrictions, which determine, in fact, the time scales from above of depletion of an electric field due to the backreactionComment: 7 pages; version accepted for publication in Phys. Rev. Lett.; added one ref. and some comment
    corecore