A. Babic
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
A. Babic has a total of 4 co-authors. Here are the top co-authors by number of shared publications:
- Branko Guberina
Rudjer Bošković Institute P.O.B. 180 10002 Zagreb Croatia
4 shared publications - Raul Horvat
Rudjer Bošković Institute, Zagreb, Croatia
4 shared publications - Hrvoje Stefancic
Theoretical Physics Division Rudjer Bošković Institute P.O.Box 180 HR-10002 Zagreb Croatia
3 shared publications H. Štefančić
Rudjer Bošković Institute, P.O.Box 180, HR-10002 Zagreb, Croatia
1 shared publication
Latest Publications
- 29 June 2005
- Published by American Physical Society (APS) in Physical Review D
- Vol. 71 (12) , 124041
Renormalization-group running cosmologies: A scale-setting procedure
For cosmologies including scale dependence of both the cosmological and the gravitational constant, an additional consistency condition dictated by the Bianchi identities emerges, even if the energy-momentum tensor of ordinary matter stays individually conserved. For renormalization-group (RG) approaches it is shown that such a consistency relation ineluctably fixes the RG scale (which may have an explicit as well as an implicit time dependence), provided that the solutions of the RG equation for both quantities are known. Hence, contrary to the procedures employed in the recent literature, we argue that there is no more freedom in identification of the RG scale in terms of the cosmic time in such cosmologies. We carefully set the RG scale for the RG evolution phrased in a quantum-gravity framework based on the hypothetical existence of an infrared fixed point, for the perturbative regime within the same framework, as well as for an evolution within quantum field theory in a curved background. In the latter case, the implications of the scale setting for the particle spectrum are also briefly discussed.
- 29 June 2005
- Published by American Physical Society (APS) in Physical Review D
- Vol. 71 (12) , 124041
Renormalization-group running cosmologies: A scale-setting procedure
For cosmologies including scale dependence of both the cosmological and the gravitational constant, an additional consistency condition dictated by the Bianchi identities emerges, even if the energy-momentum tensor of ordinary matter stays individually conserved. For renormalization-group (RG) approaches it is shown that such a consistency relation ineluctably fixes the RG scale (which may have an explicit as well as an implicit time dependence), provided that the solutions of the RG equation for both quantities are known. Hence, contrary to the procedures employed in the recent literature, we argue that there is no more freedom in identification of the RG scale in terms of the cosmic time in such cosmologies. We carefully set the RG scale for the RG evolution phrased in a quantum-gravity framework based on the hypothetical existence of an infrared fixed point, for the perturbative regime within the same framework, as well as for an evolution within quantum field theory in a curved background. In the latter case, the implications of the scale setting for the particle spectrum are also briefly discussed.
- Open Access
Renormalization-group running cosmologies - a scale-setting procedure
For cosmologies including scale dependence of both the cosmological and the gravitational constant, an additional consistency condition dictated by the Bianchi identities emerges, even if the energy-momentum tensor of ordinary matter stays individually conserved. For renormalization-group (RG) approaches it is shown that such a consistency relation ineluctably fixes the RG scale (which may have an explicit as well as an implicit time dependence), provided that the solutions of the RG equation for both quantities are known. Hence, contrary to the procedures employed in the recent literature, we argue that there is no more freedom in identification of the RG scale in terms of the cosmic time in such cosmologies. We carefully set the RG scale for the RG evolution phrased in a quantum gravity framework based on the hypothetical existence of an infrared (IR) fixed point, for the perturbative regime within the same framework, as well as for an evolution within quantum field theory (QFT) in a curved background. In the latter case, the implications of the scale setting for the particle spectrum are also briefly discussed.
Open AccessRenormalization-group running cosmologies - a scale-setting procedure
For cosmologies including scale dependence of both the cosmological and the gravitational constant, an additional consistency condition dictated by the Bianchi identities emerges, even if the energy-momentum tensor of ordinary matter stays individually conserved. For renormalization-group (RG) approaches it is shown that such a consistency relation ineluctably fixes the RG scale (which may have an explicit as well as an implicit time dependence), provided that the solutions of the RG equation for both quantities are known. Hence, contrary to the procedures employed in the recent literature, we argue that there is no more freedom in identification of the RG scale in terms of the cosmic time in such cosmologies. We carefully set the RG scale for the RG evolution phrased in a quantum gravity framework based on the hypothetical existence of an infrared (IR) fixed point, for the perturbative regime within the same framework, as well as for an evolution within quantum field theory (QFT) in a curved background. In the latter case, the implications of the scale setting for the particle spectrum are also briefly discussed.
- 8 March 2002
- Published by American Physical Society (APS) in Physical Review D
- Vol. 65 (8) , 085002
Renormalization-group running of the cosmological constant and its implication for the Higgs boson mass in the standard model
The renormalization-group equation for the zero-point energies associated with vacuum fluctuations of massive fields from the standard model is examined. Our main observation is that at any scale the running is necessarily dominated by the heaviest degrees of freedom, in clear contradistinction with the Appelquist-Carazzone decoupling theorem. Such an enhanced running would represent a disaster for cosmology, unless a fine-tuned relation among the masses of heavy particles is imposed. In this way, we obtain for the Higgs boson mass, a value safely within the unitarity bound, but far above the more stringent triviality bound for the case when the validity of the standard model is pushed up to the grand unification (or Planck) scale.- 8 March 2002
- Published by American Physical Society (APS) in Physical Review D
- Vol. 65 (8) , 085002
Renormalization-group running of the cosmological constant and its implication for the Higgs boson mass in the standard model
The renormalization-group equation for the zero-point energies associated with vacuum fluctuations of massive fields from the standard model is examined. Our main observation is that at any scale the running is necessarily dominated by the heaviest degrees of freedom, in clear contradistinction with the Appelquist-Carazzone decoupling theorem. Such an enhanced running would represent a disaster for cosmology, unless a fine-tuned relation among the masses of heavy particles is imposed. In this way, we obtain for the Higgs boson mass, a value safely within the unitarity bound, but far above the more stringent triviality bound for the case when the validity of the standard model is pushed up to the grand unification (or Planck) scale.- Open Access
Renormalization-group running of the cosmological constant and its implication for the Higgs boson mass in the Standard Model
The renormalization-group equation for the zero-point energies associated with vacuum fluctuations of massive fields from the Standard Model is examined. Our main observation is that at any scale the running is necessarily dominated by the heaviest degrees of freedom, in clear contradistinction with the Appelquist & Carazzone decoupling theorem. Such an enhanced running would represent a disaster for cosmology, unless a fine-tuned relation among the masses of heavy particles is imposed. In this way, we obtain $m_H \simeq 550 GeV$ for the Higgs mass, a value safely within the unitarity bound, but far above the more stringent triviality bound for the case when the validity of the Standard Model is pushed up to the grand unification (or Planck) scale.Open AccessRenormalization-group running of the cosmological constant and its implication for the Higgs boson mass in the Standard Model
The renormalization-group equation for the zero-point energies associated with vacuum fluctuations of massive fields from the Standard Model is examined. Our main observation is that at any scale the running is necessarily dominated by the heaviest degrees of freedom, in clear contradistinction with the Appelquist & Carazzone decoupling theorem. Such an enhanced running would represent a disaster for cosmology, unless a fine-tuned relation among the masses of heavy particles is imposed. In this way, we obtain $m_H \simeq 550 GeV$ for the Higgs mass, a value safely within the unitarity bound, but far above the more stringent triviality bound for the case when the validity of the Standard Model is pushed up to the grand unification (or Planck) scale.