Roberto Casalbuoni - Academia.edu (original) (raw)
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Papers by Roberto Casalbuoni
Concise Encyclopedia of Supersymmetry, 2004
arXiv: History and Philosophy of Physics, 2018
The figure of Raoul Gatto, who died in 2017, is remembered here, with an illustration of his care... more The figure of Raoul Gatto, who died in 2017, is remembered here, with an illustration of his career and the main results of his research, along with the personal memories of some of those who worked with him.
Journal of High Energy Physics, 2020
Starting from the coadjoint Poincaré algebra we construct a point particle relativistic model wit... more Starting from the coadjoint Poincaré algebra we construct a point particle relativistic model with an interpretation in terms of extra-dimensional variables. The starting coadjoint Poincaré algebra is able to induce a mechanism of dimensional reduction between the usual coordinates of the Minkowski space and the extra-dimensional variables which turn out to form an antisymmetric tensor under the Lorentz group. Analysing the dynamics of this model, we find that, in a particular limit, it is possible to integrate out the extra variables and determine their effect on the dynamics of the material point in the usual space time. The model describes a particle in D dimensions subject to a harmonic motion when one of the parameters of the model is negative. The result can be interpreted as a modification to the flat Minkowski metric with non trivial Riemann, Ricci tensors and scalar curvature.
![Research paper thumbnail of OSp[D+1,3 | 2] unifies the conformal symmetry and BRST](https://attachments.academia-assets.com/113183357/thumbnails/1.jpg)
](Physics Letters B, 1987
We show that the conformal transformations on the invariant metric of OSp [D, 212 ], which is the... more We show that the conformal transformations on the invariant metric of OSp [D, 212 ], which is the group unifying Lorentz and BRST symmetries, are generated by OSp[D+ 1,312], which thus unifies the conformal and BRST symmetries. We explicitly construct the generators for the scalar and for the spinning particle. We express the generators in terms of the energy-momentum tensor and study their action on the fields. We also study the linear realization of OSp [ D + 1, 312 ] on a space of D + 4 bosonic and 2 fermionic variables. Field quantization is also examined.
International Journal of Modern Physics A, 2021
In this paper, we show that a quadratic Lagrangian, with no constraints, containing ordinary time... more In this paper, we show that a quadratic Lagrangian, with no constraints, containing ordinary time derivatives up to the order [Formula: see text] of [Formula: see text] dynamical variables, has [Formula: see text] symmetries consisting in the translation of the variables with solutions of the equations of motion. We construct explicitly the generators of these transformations and prove that they satisfy the Heisenberg algebra. We also analyze other specific cases which are not included in our previous statement: the Klein–Gordon Lagrangian, [Formula: see text] Fermi oscillators and the Dirac Lagrangian. In the first case, the system is described by an equation involving partial derivatives, the second case is described by Grassmann variables and the third shows both features. Furthermore, the Fermi oscillator and the Dirac field Lagrangians lead to second class constraints. We prove that also in these last two cases there are translational symmetries and we construct the algebra of ...
Physical Review D, 2018
We introduce a general method to construct, directly in configuration space, classes of dynamical... more We introduce a general method to construct, directly in configuration space, classes of dynamical systems invariant under generalizations of the Carroll and of the Galilei groups. The method does not make use of any non-relativistiv limiting procedure, although the starting point is a lagrangian Poincaré invariant in the full space. It consists in considering a space-time in D + 1 dimensions and partitioning it in two parts, the first Minkowskian and the second Euclidean. The action consists of two terms that are separately invariant under the Minkowskian and Euclidean partitioning. One of those contains a system of lagrangian multipliers that confine the system to a subspace. The other term defines the dynamics of the system. The total lagrangian is invariant under the Carroll or the Galilei groups with zero central charge.
Concise Encyclopedia of Supersymmetry, 2004
Physics Letters B, 1987
ABSTRACT
The status of precision electroweak measurements as of summer 2002 is reviewed. The recent result... more The status of precision electroweak measurements as of summer 2002 is reviewed. The recent results on the anomalous magnetic moment of the muon and on neutrino-nucleon scattering are discussed. Precision results on the electroweak interaction obtained by the experiments at the SLC, LEP and TEVATRON colliders are presented. The experimental results are compared with the predictions of the minimal Standard Model and are used to constrain its parameters, including the mass of the Higgs boson. The final LEP results on the direct search for the Higgs boson of the Standard Model are presented. Plenary talk presented at the 31st International Conference on High Energy Physics, Amsterdam, The Netherlands, July 24-31, 2002
AIP Conference Proceedings, 2001
In this talk I discuss the relevance of atomic physics in understanding some important questions ... more In this talk I discuss the relevance of atomic physics in understanding some important questions about elementary particle physics. A particular attention is devoted to atomic parity violation measurements which seem to suggest new physics beyond the Standard Model. Atomic physics might also be relevant in discovering possible violations of the CPT symmetry.
Il Colle Di Galileo, 2012
Lettere Al Nuovo Cimento Series 2, 1979
Concise Encyclopedia of Supersymmetry, 2004
arXiv: History and Philosophy of Physics, 2018
The figure of Raoul Gatto, who died in 2017, is remembered here, with an illustration of his care... more The figure of Raoul Gatto, who died in 2017, is remembered here, with an illustration of his career and the main results of his research, along with the personal memories of some of those who worked with him.
Journal of High Energy Physics, 2020
Starting from the coadjoint Poincaré algebra we construct a point particle relativistic model wit... more Starting from the coadjoint Poincaré algebra we construct a point particle relativistic model with an interpretation in terms of extra-dimensional variables. The starting coadjoint Poincaré algebra is able to induce a mechanism of dimensional reduction between the usual coordinates of the Minkowski space and the extra-dimensional variables which turn out to form an antisymmetric tensor under the Lorentz group. Analysing the dynamics of this model, we find that, in a particular limit, it is possible to integrate out the extra variables and determine their effect on the dynamics of the material point in the usual space time. The model describes a particle in D dimensions subject to a harmonic motion when one of the parameters of the model is negative. The result can be interpreted as a modification to the flat Minkowski metric with non trivial Riemann, Ricci tensors and scalar curvature.
Physics Letters B, 1987
We show that the conformal transformations on the invariant metric of OSp [D, 212 ], which is the... more We show that the conformal transformations on the invariant metric of OSp [D, 212 ], which is the group unifying Lorentz and BRST symmetries, are generated by OSp[D+ 1,312], which thus unifies the conformal and BRST symmetries. We explicitly construct the generators for the scalar and for the spinning particle. We express the generators in terms of the energy-momentum tensor and study their action on the fields. We also study the linear realization of OSp [ D + 1, 312 ] on a space of D + 4 bosonic and 2 fermionic variables. Field quantization is also examined.
International Journal of Modern Physics A, 2021
In this paper, we show that a quadratic Lagrangian, with no constraints, containing ordinary time... more In this paper, we show that a quadratic Lagrangian, with no constraints, containing ordinary time derivatives up to the order [Formula: see text] of [Formula: see text] dynamical variables, has [Formula: see text] symmetries consisting in the translation of the variables with solutions of the equations of motion. We construct explicitly the generators of these transformations and prove that they satisfy the Heisenberg algebra. We also analyze other specific cases which are not included in our previous statement: the Klein–Gordon Lagrangian, [Formula: see text] Fermi oscillators and the Dirac Lagrangian. In the first case, the system is described by an equation involving partial derivatives, the second case is described by Grassmann variables and the third shows both features. Furthermore, the Fermi oscillator and the Dirac field Lagrangians lead to second class constraints. We prove that also in these last two cases there are translational symmetries and we construct the algebra of ...
Physical Review D, 2018
We introduce a general method to construct, directly in configuration space, classes of dynamical... more We introduce a general method to construct, directly in configuration space, classes of dynamical systems invariant under generalizations of the Carroll and of the Galilei groups. The method does not make use of any non-relativistiv limiting procedure, although the starting point is a lagrangian Poincaré invariant in the full space. It consists in considering a space-time in D + 1 dimensions and partitioning it in two parts, the first Minkowskian and the second Euclidean. The action consists of two terms that are separately invariant under the Minkowskian and Euclidean partitioning. One of those contains a system of lagrangian multipliers that confine the system to a subspace. The other term defines the dynamics of the system. The total lagrangian is invariant under the Carroll or the Galilei groups with zero central charge.
Concise Encyclopedia of Supersymmetry, 2004
Physics Letters B, 1987
ABSTRACT
The status of precision electroweak measurements as of summer 2002 is reviewed. The recent result... more The status of precision electroweak measurements as of summer 2002 is reviewed. The recent results on the anomalous magnetic moment of the muon and on neutrino-nucleon scattering are discussed. Precision results on the electroweak interaction obtained by the experiments at the SLC, LEP and TEVATRON colliders are presented. The experimental results are compared with the predictions of the minimal Standard Model and are used to constrain its parameters, including the mass of the Higgs boson. The final LEP results on the direct search for the Higgs boson of the Standard Model are presented. Plenary talk presented at the 31st International Conference on High Energy Physics, Amsterdam, The Netherlands, July 24-31, 2002
AIP Conference Proceedings, 2001
In this talk I discuss the relevance of atomic physics in understanding some important questions ... more In this talk I discuss the relevance of atomic physics in understanding some important questions about elementary particle physics. A particular attention is devoted to atomic parity violation measurements which seem to suggest new physics beyond the Standard Model. Atomic physics might also be relevant in discovering possible violations of the CPT symmetry.
Il Colle Di Galileo, 2012
Lettere Al Nuovo Cimento Series 2, 1979