Daniel Zwanziger
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Daniel Zwanziger has a total of 16 co-authors. Here are the top co-authors by number of shared publications:
- Laurent Baulieu
LPTHE, Sorbonne Université, CNRS
11 shared publications - Attilio Cucchieri
IFSC-USP Caixa Postal 369 13560-970 São Carlos SP Brazil
6 shared publications - Nele Vandersickel
Ghent University
4 shared publications - David Dudal
KU Leuven
3 shared publications - Jeff Greensite
San Francisco State University
3 shared publications - Marcelo Santos Guimaraes
UERJ-Universidade do Estado do Rio de Janeiro
3 shared publications
Latest Publications
- Open Access
- 21 May 2015
- Published by Sissa Medialab Srl
- Vol. 214, 362
two-dimensional phase structure of SU(2) gauge-Higgs model
- 21 May 2015
- Published by Sissa Medialab Srl
- Vol. 214, 362
Open Accesstwo-dimensional phase structure of SU(2) gauge-Higgs model
- Open Access
- 7 January 2015
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2015 (1) , 1-17
Phase structure and the gluon propagator of SU(2) gauge-Higgs model in two dimensions
- 7 January 2015
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2015 (1) , 1-17
Open AccessPhase structure and the gluon propagator of SU(2) gauge-Higgs model in two dimensions
- 24 April 2013
- Published by American Physical Society (APS) in Physical Review D
- Vol. 87 (8)
Minimizing gauge functional for 2d gravity and string theory
We show the existence of a minimizing procedure for selecting a unique representative on the orbit of any given Riemann surface that contributes to the string partition function. As it must, the procedure reduces the string path integral to a final integration over a particular fundamental domain, selected by the choice of the minimizing functional. This construction somehow demystifies the Gribov question.
- 24 April 2013
- Published by American Physical Society (APS) in Physical Review D
- Vol. 87 (8)
Minimizing gauge functional for 2d gravity and string theory
We show the existence of a minimizing procedure for selecting a unique representative on the orbit of any given Riemann surface that contributes to the string partition function. As it must, the procedure reduces the string path integral to a final integration over a particular fundamental domain, selected by the choice of the minimizing functional. This construction somehow demystifies the Gribov question.
- Open Access
Minimizing gauge-functional for 2-d gravity and string theory
We show the existence of a minimizing procedure for selecting a unique representative on the orbit of any given Riemann surface that contributes to the string partition function. As it must, the procedure reduces the string path integral to a final integration over a particular fundamental domain, selected by the choice of the minimizing functional. This construction somehow demystifies the Gribov question.
Open AccessMinimizing gauge-functional for 2-d gravity and string theory
We show the existence of a minimizing procedure for selecting a unique representative on the orbit of any given Riemann surface that contributes to the string partition function. As it must, the procedure reduces the string path integral to a final integration over a particular fundamental domain, selected by the choice of the minimizing functional. This construction somehow demystifies the Gribov question.
- Open Access
The Gribov problem and QCD dynamics
In 1967, Faddeev and Popov were able to quantize the Yang-Mills theory by introducing new particles called ghost through the introduction of a gauge. Ever since, this quantization has become a standard textbook item. Some years later, Gribov discovered that the gauge fixing was not complete, gauge copies called Gribov copies were still present and could affect the infrared region of quantities like the gauge dependent gluon and ghost propagator. This feature was often in literature related to confinement. Some years later, the semi-classical approach of Gribov was generalized to all orders and the so-called GZ action was born. Ever since, many related articles were published. This review tends to give a pedagogic review of the ideas of Gribov and the subsequent construction of the GZ action, including many other toipics related to the Gribov region. It is shown how the GZ action can be viewed as a non-perturbative tool which has relations with other approaches towards confinement. Many different features related to the GZ action shall be discussed in detail, such as BRST breaking, the KO criterion, the propagators, etc. We shall also compare with the lattice data and other non-perturbative approaches, including stochastic quantization.
Open AccessThe Gribov problem and QCD dynamics
In 1967, Faddeev and Popov were able to quantize the Yang-Mills theory by introducing new particles called ghost through the introduction of a gauge. Ever since, this quantization has become a standard textbook item. Some years later, Gribov discovered that the gauge fixing was not complete, gauge copies called Gribov copies were still present and could affect the infrared region of quantities like the gauge dependent gluon and ghost propagator. This feature was often in literature related to confinement. Some years later, the semi-classical approach of Gribov was generalized to all orders and the so-called GZ action was born. Ever since, many related articles were published. This review tends to give a pedagogic review of the ideas of Gribov and the subsequent construction of the GZ action, including many other toipics related to the Gribov region. It is shown how the GZ action can be viewed as a non-perturbative tool which has relations with other approaches towards confinement. Many different features related to the GZ action shall be discussed in detail, such as BRST breaking, the KO criterion, the propagators, etc. We shall also compare with the lattice data and other non-perturbative approaches, including stochastic quantization.
- Open Access
From unphysical gluon and ghost propagators to physical glueball propagators (in the Gribov-Zwanziger picture): a not so trivial task?
During recent years, a good agreement was found between the analytical derivation and the numerical simulation of the Landau gauge gluon and ghost propagators. We mention the Schwinger-Dyson and Gribov-Zwanziger formalism for the analytical work. Although the agreement between several approaches is nice, these propagators do not correspond to the relevant physical degrees of freedom. In the case of pure gauge theories, one should start to study the glueball correlators. We shall try to explain why it looks like a hard challenge to go from the unphysical to the physical propagators in the case of the Gribov-Zwanziger theory (but similar conclusions might hold for other approaches giving similar propagators).
Open AccessFrom unphysical gluon and ghost propagators to physical glueball propagators (in the Gribov-Zwanziger picture): a not so trivial task?
During recent years, a good agreement was found between the analytical derivation and the numerical simulation of the Landau gauge gluon and ghost propagators. We mention the Schwinger-Dyson and Gribov-Zwanziger formalism for the analytical work. Although the agreement between several approaches is nice, these propagators do not correspond to the relevant physical degrees of freedom. In the case of pure gauge theories, one should start to study the glueball correlators. We shall try to explain why it looks like a hard challenge to go from the unphysical to the physical propagators in the case of the Gribov-Zwanziger theory (but similar conclusions might hold for other approaches giving similar propagators).
- Open Access
Gribov horizon and i-particles: about a toy model and the construction of physical operators
Restricting the functional integral to the Gribov region $\Omega$ leads to a deep modification of the behavior of Euclidean Yang-Mills theories in the infrared region. For example, a gluon propagator of the Gribov type, $\frac{k^2}{k^4+{\hat \gamma}^4}$, can be viewed as a propagating pair of unphysical modes, called here $i$-particles, with complex masses $\pm i{\hat \gamma}^2$. From this viewpoint, gluons are unphysical and one can see them as being confined. We introduce a simple toy model describing how a suitable set of composite operators can be constructed out of $i$-particles whose correlation functions exhibit only real branch cuts, with associated positive spectral density. These composite operators can thus be called physical and are the toy analogy of glueballs in the Gribov-Zwanziger theory.Open AccessGribov horizon and i-particles: about a toy model and the construction of physical operators
Restricting the functional integral to the Gribov region $\Omega$ leads to a deep modification of the behavior of Euclidean Yang-Mills theories in the infrared region. For example, a gluon propagator of the Gribov type, $\frac{k^2}{k^4+{\hat \gamma}^4}$, can be viewed as a propagating pair of unphysical modes, called here $i$-particles, with complex masses $\pm i{\hat \gamma}^2$. From this viewpoint, gluons are unphysical and one can see them as being confined. We introduce a simple toy model describing how a suitable set of composite operators can be constructed out of $i$-particles whose correlation functions exhibit only real branch cuts, with associated positive spectral density. These composite operators can thus be called physical and are the toy analogy of glueballs in the Gribov-Zwanziger theory. - 30 July 2010
- Published by American Physical Society (APS) in Physical Review D
- Vol. 82 (2) , 025021
Gribov horizon and-particles: About a toy model and the construction of physical operatorsRestricting the functional integral to the Gribov region leads to a deep modification of the behavior of Euclidean Yang-Mills theories in the infrared region. For example, a gluon propagator of the Gribov type, , can be viewed as a propagating pair of unphysical modes, called here -particles, with complex masses . From this viewpoint, gluons are unphysical and one can see them as being confined. We introduce a simple toy model describing how a suitable set of composite operators can be constructed out of -particles whose correlation functions exhibit only real branch cuts, with associated positive spectral density. These composite operators can thus be called physical and are the toy analogy of glueballs in the Gribov-Zwanziger theory.- 30 July 2010
- Published by American Physical Society (APS) in Physical Review D
- Vol. 82 (2) , 025021
Gribov horizon and-particles: About a toy model and the construction of physical operatorsRestricting the functional integral to the Gribov region leads to a deep modification of the behavior of Euclidean Yang-Mills theories in the infrared region. For example, a gluon propagator of the Gribov type, , can be viewed as a propagating pair of unphysical modes, called here -particles, with complex masses . From this viewpoint, gluons are unphysical and one can see them as being confined. We introduce a simple toy model describing how a suitable set of composite operators can be constructed out of -particles whose correlation functions exhibit only real branch cuts, with associated positive spectral density. These composite operators can thus be called physical and are the toy analogy of glueballs in the Gribov-Zwanziger theory.- Open Access
Contributions to the QCD Pressure Beyond Perturbation Theory
In this article we report on a new proposal to treat the infrared problems of thermal QCD by taking into account explicitly the confining influence of the Gribov horizon. In order to make clear the possible value of such an approach, we briefly review the most important arguments why a straightforward perturbative description of finite-temperature QCD is unlikely to be successful. From the infrared problems of thermal perturbation theory one can conclude that confinement effects and bound states probably play an important role also in the high-temperature phase. To set the stage we recount the supposed role of the Gribov horizon for confinement, before we turn to the application to finite-temperature theory. In the current approach it has been found that the contributions to the free energy from the explicit inclusion of the horizon begin to set in at order $g^6$ -- precisely where the infrared problems of thermal QCD lead to a breakdown of ordinary perturbation theory. From the study of observables (free energy, anomaly, bulk viscosity) we also note that for thermodynamic observables the leading order term obtained by such an expansion in the coupling strongly deviates from the more complete numerical solution. This can be regarded as yet another sign for general problems of series expansions in thermal QCD.Open AccessContributions to the QCD Pressure Beyond Perturbation Theory
In this article we report on a new proposal to treat the infrared problems of thermal QCD by taking into account explicitly the confining influence of the Gribov horizon. In order to make clear the possible value of such an approach, we briefly review the most important arguments why a straightforward perturbative description of finite-temperature QCD is unlikely to be successful. From the infrared problems of thermal perturbation theory one can conclude that confinement effects and bound states probably play an important role also in the high-temperature phase. To set the stage we recount the supposed role of the Gribov horizon for confinement, before we turn to the application to finite-temperature theory. In the current approach it has been found that the contributions to the free energy from the explicit inclusion of the horizon begin to set in at order $g^6$ -- precisely where the infrared problems of thermal QCD lead to a breakdown of ordinary perturbation theory. From the study of observables (free energy, anomaly, bulk viscosity) we also note that for thermodynamic observables the leading order term obtained by such an expansion in the coupling strongly deviates from the more complete numerical solution. This can be regarded as yet another sign for general problems of series expansions in thermal QCD. - Open Access
- 14 December 2005
- Published by Sissa Medialab Srl
Gribov horizon under the (lattice) microscope
- 14 December 2005
- Published by Sissa Medialab Srl
Open AccessGribov horizon under the (lattice) microscope