Adriano Di Giacomo
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Adriano Di Giacomo has a total of 141 co-authors. Here are the top co-authors by number of shared publications:
G. Paffuti
27 shared publicationsM. D'Elia
27 shared publications- Claudio Pica
QTC & IMADA University of Southern Denmark Campusvej 55 5230 Odense M Denmark and
23 shared publications - Biagio Lucini
Swansea University (Bay Campus)
22 shared publications B. Allés
20 shared publications- Haralambos Panagopoulos
University of Cyprus
19 shared publications
Latest Publications
- Open Access
Colour confinement and gauge-invariant field-strength correlations
In this paper we produce evidence that confinement of colour is due to dual superconductivity of $QCD$ vacuum. To do that we put together results of old numerical simulations and results of more recent investigations. The starting point is the expectation that gauge theories admit a dual description in terms of monopoles. The strategy is then to construct the creation operator $μ$ of a monopole and to compute its vacuum expectation value $\langle μ\rangle$ , the disorder parameter which indicates dual superconductivity. The Imechanism of confinement is dual superconductivity of vacuum if $\langle μ\rangle \neq 0 $ in the confined phase , and $\langle μ\rangle =0$ in the deconfined phase. Confinement has to be certified by independent methods. It is shown that gauge invariance requires that field strengths be replaced by gauge invariant field strengths, which are their parallel transports to infinity. The resulting disorder parameter is a sum of correlation functions of gauge invariant field strength, and its behaviour understood by use of existing lattice data of two-point gauge invariant correlations. As a byproduct an apparent existing inconsistency, the lack of preferred orientation in colour space of the chromo-electric field inside confining flux tubes, is resolved.Open AccessColour confinement and gauge-invariant field-strength correlations
In this paper we produce evidence that confinement of colour is due to dual superconductivity of $QCD$ vacuum. To do that we put together results of old numerical simulations and results of more recent investigations. The starting point is the expectation that gauge theories admit a dual description in terms of monopoles. The strategy is then to construct the creation operator $μ$ of a monopole and to compute its vacuum expectation value $\langle μ\rangle$ , the disorder parameter which indicates dual superconductivity. The Imechanism of confinement is dual superconductivity of vacuum if $\langle μ\rangle \neq 0 $ in the confined phase , and $\langle μ\rangle =0$ in the deconfined phase. Confinement has to be certified by independent methods. It is shown that gauge invariance requires that field strengths be replaced by gauge invariant field strengths, which are their parallel transports to infinity. The resulting disorder parameter is a sum of correlation functions of gauge invariant field strength, and its behaviour understood by use of existing lattice data of two-point gauge invariant correlations. As a byproduct an apparent existing inconsistency, the lack of preferred orientation in colour space of the chromo-electric field inside confining flux tubes, is resolved. - 25 December 2025
- Published by Elsevier in Journal of Subatomic Particles and Cosmology
- Vol. 5
Colour confinement and gauge-invariant field-strength correlations
- 25 December 2025
- Published by Elsevier in Journal of Subatomic Particles and Cosmology
- Vol. 5
Colour confinement and gauge-invariant field-strength correlations
- Open AccessGauge-invariant field strengths in $QCD$Gauge-invariant field strengths, defined as parallel transports to infinity of ordinary field strengths, naturally emerge in a few physical phenomena governed by $QCD$. One of them is confinement of colour. Despite the arbitrariness in their definition coming from the freedom in the choice of the path of the parallel transport to infinity, the request of differentiability with respect to the position $x$ strongly constrains their correlation functions. Strong constraints also come from translation and Lorentz invariance. Gauge invariant field strengths also appear in the non abelian Stokes theorem, and allow to understand basic properties of the vacuum by use of lattice data.Open AccessGauge-invariant field strengths in $QCD$Gauge-invariant field strengths, defined as parallel transports to infinity of ordinary field strengths, naturally emerge in a few physical phenomena governed by $QCD$. One of them is confinement of colour. Despite the arbitrariness in their definition coming from the freedom in the choice of the path of the parallel transport to infinity, the request of differentiability with respect to the position $x$ strongly constrains their correlation functions. Strong constraints also come from translation and Lorentz invariance. Gauge invariant field strengths also appear in the non abelian Stokes theorem, and allow to understand basic properties of the vacuum by use of lattice data.
- Open Access
- 24 February 2021
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2021 (2) , 1-25
A gauge invariant order parameter for monopole condensation in QCD vacuum
In this paper we improve the existing order parameter for monopole condensation in gauge theory vacuum, making it gauge-invariant from scratch and free of the spurious infrared problems which plagued the old one. Computing the new parameter on the lattice will unambiguously detect weather dual superconductivity is the mechanism for color confinement.As a byproduct we relate confinement to the existence of a finite correlation length in the gauge-invariant correlator of chromo-electric field strengths.
- 24 February 2021
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2021 (2) , 1-25
Open AccessA gauge invariant order parameter for monopole condensation in QCD vacuum
In this paper we improve the existing order parameter for monopole condensation in gauge theory vacuum, making it gauge-invariant from scratch and free of the spurious infrared problems which plagued the old one. Computing the new parameter on the lattice will unambiguously detect weather dual superconductivity is the mechanism for color confinement.As a byproduct we relate confinement to the existence of a finite correlation length in the gauge-invariant correlator of chromo-electric field strengths.
- Open AccessA gauge invariant order parameter for monopole condensation in $QCD$ vacuum
In this paper we improve the existing order parameter for monopole condensation in gauge theory vacuum, making it gauge-invariant from scratch and free of the spurious infrared problems which plagued the old one. Computing the new parameter on the lattice will unambiguously detect weather dual superconductivity is the mechanism for color confinement. As a byproduct we relate confinement to the existence of a finite correlation length in the gauge-invariant correlator of chromo-electric field strengths.
Open AccessA gauge invariant order parameter for monopole condensation in $QCD$ vacuumIn this paper we improve the existing order parameter for monopole condensation in gauge theory vacuum, making it gauge-invariant from scratch and free of the spurious infrared problems which plagued the old one. Computing the new parameter on the lattice will unambiguously detect weather dual superconductivity is the mechanism for color confinement. As a byproduct we relate confinement to the existence of a finite correlation length in the gauge-invariant correlator of chromo-electric field strengths.
- Open Access
- 14 November 2018
- Published by EDP Sciences in EPJ Web of Conferences
- Vol. 192, 00001
Confinement, Monopoles and Gauge Invariance
The status is reviewed of the lattice studies of confinement by dual superconductivity of QCD vacuum. Progress is made by proving that the existence and the creation of a monopole are gauge invariant concepts. This proof fully legitimates an existing order parameter, and with it the evidence it provides of monopole condensation in the confining vacuum.
- 14 November 2018
- Published by EDP Sciences in EPJ Web of Conferences
- Vol. 192, 00001
Open AccessConfinement, Monopoles and Gauge Invariance
The status is reviewed of the lattice studies of confinement by dual superconductivity of QCD vacuum. Progress is made by proving that the existence and the creation of a monopole are gauge invariant concepts. This proof fully legitimates an existing order parameter, and with it the evidence it provides of monopole condensation in the confining vacuum.
- Open Access
- 15 July 2016
- Published by Sissa Medialab Srl
- Vol. 251, 313
Chiral symmetry breaking, instantons, and monopoles
- 15 July 2016
- Published by Sissa Medialab Srl
- Vol. 251, 313
Open AccessChiral symmetry breaking, instantons, and monopoles
- Open Access
- 20 June 2016
- Published by Sissa Medialab Srl
- Vol. 253, 127
Chiral symmetry breaking and monopoles
- 20 June 2016
- Published by Sissa Medialab Srl
- Vol. 253, 127
Open AccessChiral symmetry breaking and monopoles
- Open Access
Chiral symmetry breaking and monopoles
To understand the relation between the chiral symmetry breaking and monopoles, the chiral condensate which is the order parameter of the chiral symmetry breaking is calculated in the $\overline{\mbox{MS}}$ scheme at 2 [GeV]. First, we add one pair of monopoles, varying the monopole charges $m_{c}$ from zero to four, to SU(3) quenched configurations by a monopole creation operator. The low-lying eigenvalues of the Overlap Dirac operator are computed from the gauge links of the normal configurations and the configurations with additional monopoles. Next, we compare the distributions of the nearest-neighbor spacing of the low-lying eigenvalues with the prediction of the random matrix theory. The low-lying eigenvalues not depending on the scale parameter $\Sigma$ are compared to the prediction of the random matrix theory. The results show the consistency with the random matrix theory. Thus, the additional monopoles do not affect the low-lying eigenvalues. Moreover, we discover that the additional monopoles increase the scale parameter $\Sigma$. We then evaluate the chiral condensate in the $\overline{\mbox{MS}}$ scheme at 2 [GeV] from the scale parameter $\Sigma$ and the renormalization constant $Z_{S}$. The final results clearly show that the chiral condensate linearly decreases by increasing the monopole charges.Open AccessChiral symmetry breaking and monopoles
To understand the relation between the chiral symmetry breaking and monopoles, the chiral condensate which is the order parameter of the chiral symmetry breaking is calculated in the $\overline{\mbox{MS}}$ scheme at 2 [GeV]. First, we add one pair of monopoles, varying the monopole charges $m_{c}$ from zero to four, to SU(3) quenched configurations by a monopole creation operator. The low-lying eigenvalues of the Overlap Dirac operator are computed from the gauge links of the normal configurations and the configurations with additional monopoles. Next, we compare the distributions of the nearest-neighbor spacing of the low-lying eigenvalues with the prediction of the random matrix theory. The low-lying eigenvalues not depending on the scale parameter $\Sigma$ are compared to the prediction of the random matrix theory. The results show the consistency with the random matrix theory. Thus, the additional monopoles do not affect the low-lying eigenvalues. Moreover, we discover that the additional monopoles increase the scale parameter $\Sigma$. We then evaluate the chiral condensate in the $\overline{\mbox{MS}}$ scheme at 2 [GeV] from the scale parameter $\Sigma$ and the renormalization constant $Z_{S}$. The final results clearly show that the chiral condensate linearly decreases by increasing the monopole charges. - 1 January 2016
- Published by AIP Publishing in AIP Conference Proceedings
- Vol. 1701, 100008
Zero modes, instantons, and monopoles
The purpose of this study is to show the relations between monopoles instantons and Chiral symmetry breaking. First, in order to show the relation between instantons and monopoles, we generate configurations, adding monopoles by a monopole creation operator. Then, we count the number of fermion zero modes in the configurations using Overlap fermions as a tool. As a result we find that one monopole with plus one charge and one anti-monopole with minus one charge make one instanton of charge plus or minus one. We have already reported these results elsewhere. In addition, in this report, the relation between the additional monopoles and Chiral symmetry breaking is discussed. We compute the Chiral condensate, the pseudo-scalar mass, and the pion decay constant. Preliminary results show that the additional monopoles do affect Chiral symmetry breaking.
- 1 January 2016
- Published by AIP Publishing in AIP Conference Proceedings
- Vol. 1701, 100008
Zero modes, instantons, and monopoles
The purpose of this study is to show the relations between monopoles instantons and Chiral symmetry breaking. First, in order to show the relation between instantons and monopoles, we generate configurations, adding monopoles by a monopole creation operator. Then, we count the number of fermion zero modes in the configurations using Overlap fermions as a tool. As a result we find that one monopole with plus one charge and one anti-monopole with minus one charge make one instanton of charge plus or minus one. We have already reported these results elsewhere. In addition, in this report, the relation between the additional monopoles and Chiral symmetry breaking is discussed. We compute the Chiral condensate, the pseudo-scalar mass, and the pion decay constant. Preliminary results show that the additional monopoles do affect Chiral symmetry breaking.