Gian Paolo Vacca | Istituto Nazionale di Fisica Nucleare (original) (raw)

Uploads

Papers by Gian Paolo Vacca

Research paper thumbnail of Vacuum energy, Standard Model physics and the <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>750</mn><mtext>  </mtext><mrow><mi mathvariant="normal">G</mi><mi mathvariant="normal">e</mi><mi mathvariant="normal">V</mi></mrow></mrow><annotation encoding="application/x-tex">750\; \rm{GeV}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord">750</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mord"><span class="mord"><span class="mord mathrm" style="margin-right:0.01389em;">GeV</span></span></span></span></span></span> Diphoton Excess at the LHC

arXiv (Cornell University), Apr 8, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Energy-Momentum Tensor of Quantum Fluctuations in Chaotic Φ2 Inflation

ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an... more ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an inflationary universe driven by a massive scalar field is presented and compared with the known results in de Sitter space-time. When metric fluctuations are included, the renormalized EMT is characterized by a negative energy density which grows in time during the inflationary regime. We also approach the back-reaction problem as a second-order calculation in perturbation theory, and find that the average expansion rate is decreased, in agreement with the result on the EMT. Finally, we discuss common concerns and the implications of our results.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Are there scaling solutions in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>O</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>N</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>-models for large<mml:math xmlns:mml="http://www.w3...

Physical review, Nov 17, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The odderon and BKP states in the Quantum Chromodynamics

arXiv (Cornell University), Jan 15, 2020

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A geometrical instability for ultra-light fields during inflation?

Journal of Cosmology and Astroparticle Physics, Dec 20, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Triple pomeron vertex in the limit <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>N</mi><mi>c</mi></msub><mo>→</mo><mi mathvariant="normal">∞</mi></mrow><annotation encoding="application/x-tex">N_c\rightarrow\infty</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10903em;">N</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.109em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">c</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">→</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord">∞</span></span></span></span>

European Physical Journal C, 1999

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Flow equation for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>gravity and some of its exact solutions

Physical review, Sep 8, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Odderon and BKP States in Quantum Chromodynamics

WORLD SCIENTIFIC eBooks, Nov 1, 2021

Bookmarks Related papers MentionsView impact

Research paper thumbnail of On the choice of entropy variables in multifield inflation

arXiv (Cornell University), Jul 7, 2021

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Triple pomeron vertex in the limit Nc->8

Eur Phys J C, 1999

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Energy-Momentum Tensor of Quantum Fluctuations in Chaotic Φ 2 Inflation

Thinking, Observing and Mining the Universe, 2004

ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an... more ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an inflationary universe driven by a massive scalar field is presented and compared with the known results in de Sitter space-time. When metric fluctuations are included, the renormalized EMT is characterized by a negative energy density which grows in time during the inflationary regime. We also approach the back-reaction problem as a second-order calculation in perturbation theory, and find that the average expansion rate is decreased, in agreement with the result on the EMT. Finally, we discuss common concerns and the implications of our results.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Stochastic growth of quantum fluctuations during slow-roll inflation

Nucleation and Atmospheric Aerosols, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Multiple interactions and AGK rules in pQCD

arXiv (Cornell University), Sep 19, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Coarse-Graining in Phase Space

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Perturbative QCD Odderon and Diffractive η c Production

The Odderon state in perturbative QCD is briefly reviewed. Recent calculations devoted to estimat... more The Odderon state in perturbative QCD is briefly reviewed. Recent calculations devoted to estimate the diffrative ηc production at high energies from the leading known Odderon states are discussed.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Jet Vertex in the Next-to-Leading Log(s) Approximation

DIFFRACTION 2002: Interpretation of the New Diffractive Phenomena in Quantum Chromodynamics and in the S-Matrix Theory, 2003

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Small x QCD

A review of some theoretical aspects of small x QCD physics is given, with a particular emphasis ... more A review of some theoretical aspects of small x QCD physics is given, with a particular emphasis to the relation between the BFKL and the colour dipole approaches. The nonlinear evolution equations one may construct, as a better approximation beyond the linear analysis, are discussed together with their relation to a possible saturation regime.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Wilsonian renormalization group in the functional non-perturbative approach

International Journal of Geometric Methods in Modern Physics, 2020

We consider a functional relation between a given Wilsonian renormalization group (RG) flow, whic... more We consider a functional relation between a given Wilsonian renormalization group (RG) flow, which has to be related to a specific coarse-graining procedure, and an infinite family of (UV cutoff) scale-dependent field redefinitions. Within this framework, one can define a family of Wilsonian proper-time (PT) exact RG equations associated to an arbitrary regulator function. New applications of these RG flow schemes to the Ising Universality class in three dimensions in the derivative expansion are shortly illustrated.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Pomeron-Odderon interactions: A functional RG flow analysis

AIP Conference Proceedings, 2017

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Are there scaling solutions in theO(N)-models for largeNind>4?

Physical Review D, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Vacuum energy, Standard Model physics and the <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>750</mn><mtext>  </mtext><mrow><mi mathvariant="normal">G</mi><mi mathvariant="normal">e</mi><mi mathvariant="normal">V</mi></mrow></mrow><annotation encoding="application/x-tex">750\; \rm{GeV}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord">750</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mord"><span class="mord"><span class="mord mathrm" style="margin-right:0.01389em;">GeV</span></span></span></span></span></span> Diphoton Excess at the LHC

arXiv (Cornell University), Apr 8, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Energy-Momentum Tensor of Quantum Fluctuations in Chaotic Φ2 Inflation

ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an... more ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an inflationary universe driven by a massive scalar field is presented and compared with the known results in de Sitter space-time. When metric fluctuations are included, the renormalized EMT is characterized by a negative energy density which grows in time during the inflationary regime. We also approach the back-reaction problem as a second-order calculation in perturbation theory, and find that the average expansion rate is decreased, in agreement with the result on the EMT. Finally, we discuss common concerns and the implications of our results.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Are there scaling solutions in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>O</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>N</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>-models for large<mml:math xmlns:mml="http://www.w3...

Physical review, Nov 17, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The odderon and BKP states in the Quantum Chromodynamics

arXiv (Cornell University), Jan 15, 2020

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A geometrical instability for ultra-light fields during inflation?

Journal of Cosmology and Astroparticle Physics, Dec 20, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Triple pomeron vertex in the limit <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>N</mi><mi>c</mi></msub><mo>→</mo><mi mathvariant="normal">∞</mi></mrow><annotation encoding="application/x-tex">N_c\rightarrow\infty</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10903em;">N</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.109em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">c</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">→</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord">∞</span></span></span></span>

European Physical Journal C, 1999

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Flow equation for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>gravity and some of its exact solutions

Physical review, Sep 8, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Odderon and BKP States in Quantum Chromodynamics

WORLD SCIENTIFIC eBooks, Nov 1, 2021

Bookmarks Related papers MentionsView impact

Research paper thumbnail of On the choice of entropy variables in multifield inflation

arXiv (Cornell University), Jul 7, 2021

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Triple pomeron vertex in the limit Nc->8

Eur Phys J C, 1999

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Energy-Momentum Tensor of Quantum Fluctuations in Chaotic Φ 2 Inflation

Thinking, Observing and Mining the Universe, 2004

ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an... more ABSTRACT The study of the renormalized energy-momentum tensor (EMT) of quantum fluctuations in an inflationary universe driven by a massive scalar field is presented and compared with the known results in de Sitter space-time. When metric fluctuations are included, the renormalized EMT is characterized by a negative energy density which grows in time during the inflationary regime. We also approach the back-reaction problem as a second-order calculation in perturbation theory, and find that the average expansion rate is decreased, in agreement with the result on the EMT. Finally, we discuss common concerns and the implications of our results.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Stochastic growth of quantum fluctuations during slow-roll inflation

Nucleation and Atmospheric Aerosols, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Multiple interactions and AGK rules in pQCD

arXiv (Cornell University), Sep 19, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Coarse-Graining in Phase Space

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Perturbative QCD Odderon and Diffractive η c Production

The Odderon state in perturbative QCD is briefly reviewed. Recent calculations devoted to estimat... more The Odderon state in perturbative QCD is briefly reviewed. Recent calculations devoted to estimate the diffrative ηc production at high energies from the leading known Odderon states are discussed.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Jet Vertex in the Next-to-Leading Log(s) Approximation

DIFFRACTION 2002: Interpretation of the New Diffractive Phenomena in Quantum Chromodynamics and in the S-Matrix Theory, 2003

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Small x QCD

A review of some theoretical aspects of small x QCD physics is given, with a particular emphasis ... more A review of some theoretical aspects of small x QCD physics is given, with a particular emphasis to the relation between the BFKL and the colour dipole approaches. The nonlinear evolution equations one may construct, as a better approximation beyond the linear analysis, are discussed together with their relation to a possible saturation regime.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Wilsonian renormalization group in the functional non-perturbative approach

International Journal of Geometric Methods in Modern Physics, 2020

We consider a functional relation between a given Wilsonian renormalization group (RG) flow, whic... more We consider a functional relation between a given Wilsonian renormalization group (RG) flow, which has to be related to a specific coarse-graining procedure, and an infinite family of (UV cutoff) scale-dependent field redefinitions. Within this framework, one can define a family of Wilsonian proper-time (PT) exact RG equations associated to an arbitrary regulator function. New applications of these RG flow schemes to the Ising Universality class in three dimensions in the derivative expansion are shortly illustrated.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Pomeron-Odderon interactions: A functional RG flow analysis

AIP Conference Proceedings, 2017

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Are there scaling solutions in theO(N)-models for largeNind>4?

Physical Review D, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Symmetry and universality of multi-field interactions in 6− dimensions

We give a heuristic classification of all universality classes of critical models with up to thre... more We give a heuristic classification of all universality classes of critical models with up to three field-theoretical scalar order parameters in 6− dimensions. Each class is uniquely characterized by its symmetry group and by the set of its universal scaling properties, neither of which are built-in by the formalism but instead emerge nontrivially as outputs of our computations. In particular for three fields we find, apart for a perturbatively unitary solution with O(2) symmetry already known in the literature, five novel non-trivial universality classes with discrete symmetries and with real bounded spectra, among which there is another perturbatively unitary model. We expect them to correspond to new nontrivial CFTs in less than six dimensions.

Bookmarks Related papers MentionsView impact