Ref HAL: hal-02884262_v1
Exporter : BibTex | endNote
Résumé:

General forms of the Kähler and superpotenials that lead to consistent low energy brokenSupersymmetry originating from N = 1 Supergravity have been classified and used formodel building since more than three decades. We point out the incompleteness of thisclassification when hidden sector vacuum expectation values are of the order of the Planckmass. Focusing in this paper mainly on the case of minimal Kähler potential, we adopta rigorous approach that retrieves on the one hand the known forms, and demonstrateon the other hand the existence of a whole set of new forms for the superpotential ofwhich we give a complete classification. The latter forms involve a new type of chiralsuperfields having the unusual property of belonging neither to the hidden sector nor tothe conventional observable sector. Comparing the obtained forms with the conventionalones, we argue how new possibilities for model building can arise, and discuss the gravitymediation of soft as well as additional hard (but parametrically small) Supersymmetrybreaking, in the presence of the new type of chiral superfields. In the simplest case,we study the vacuum structure, characterize the masses and couplings of the scalarcomponents to the hidden and observable sectors and discuss briefly the physical rolethey could play. In the generic case, we estimate the magnitude and possible consequencesof the hard breaking of Supersymmetry in terms of the interplay between hidden andvisible sectors mass scales.

Ref HAL: hal-01935444_v2
Exporter : BibTex | endNote
Résumé:

In these lectures I will introduce and explore properties of the Renormalisation Group (RG) both in its discrete and continuous forms. Topics to be discussed include multi scale expansions, the RG, Gaussian fixed points, Wick products from the RG point of view, ultraviolet cutoff removal, flow equations and perturbative flows, trivial and non-trivial fixed points, and critical field theories. Rigorous Discrete RG analysis. I will discuss a rigorous application for a non-trivial fixed point.

Ref HAL: hal-01886014_v1
Ref Arxiv: 1809.07034
Ref INSPIRE: 1694683
DOI: 10.1103/PhysRevD.98.104044
WoS: 000451337400017
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
9 Citations
Résumé:

Recent analyses [S. Nesseris et al., Phys. Rev. D 96, 023543 (2017)PRVDAQ2470-001010.1103/PhysRevD.96.023543; L. Kazantzidis and L. Pervolaropoulos, Phys. Rev. D 97, 103503 (2018)PRVDAQ2470-001010.1103/PhysRevD.97.103503] have indicated that an effective Newton’s constant Geff(z) decreasing with redshift may relieve the observed tension between the Planck15 best fit ΛCDM cosmological background (i.e., Planck15/ΛCDM) and the corresponding ΛCDM background favored by growth fσ8 and weak lensing data. We investigate the consistency of such a decreasing Geff(z) with some viable scalar-tensor models and f(R) theories. We stress that f(R) theories generically cannot lead to a decreasing Geff(z) for any cosmological background. For scalar-tensor models we deduce that in the context of a ΛCDM cosmological background, a decreasing Geff(z) is not consistent with a large Brans-Dicke parameter ωBD,0 today. This inconsistency remains and amplifies in the presence of a phantom dark energy equation of state parameter (w<-1). However, it can be avoided for w>-1. We also find that any modified gravity model with the required decreasing Geff(z) and Geff,0=G would have a characteristic signature in its growth index γ with 0.61≲γ0≲0.69 and large slopes γ0′, 0.16≲γ0′≲0.4, which is a characteristic signature of a decreasing (with z) Geff(z)

Ref HAL: hal-01851263_v1
Ref Arxiv: 1807.04279
Ref INSPIRE: 1681965
DOI: 10.1007/JHEP10(2018)017
WoS: 000446567500001
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
7 Citations
Résumé:

Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charged lepton flavor and CP violating observables. We put forward a U(1)$^{3}$ × CP symmetry of the composite sector, in order to allow the new physics to be not far above the TeV scale. This hypothesis effectively suppresses the new contributions to the electron EDM and μ → eγ, by far the most constraining observables, and results in a novel pattern of flavor violation and neutrino masses. The CP violation in the elementary-composite mixing is shown to induce a CKM phase of the correct size, as well as order-one phases in the PMNS matrix. We compare with the alternative possibility of introducing multiple scales of compositeness for leptons, that also allow to evade flavor and CP constraints. Finally, we examine violations of lepton flavor universality in B-meson semi-leptonic decays. The neutral-current anomalies can be accommodated, predicting strong correlations among different lepton flavors, with a few channels close to the experimental sensitivity.

Ref HAL: hal-01820521_v1
Ref Arxiv: 1803.09931
DOI: 10.1007/s11005-018-1128-2
WoS: 000460657200005
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
1 Citation
Résumé:

We introduce the notion of $N$-reflection equation which provides a large generalization of the usual classical reflection equation describing integrable boundary conditions. The latter is recovered as a special example of the $N=2$ case. The basic theory is established and illustrated with several examples of solutions of the $N$-reflection equation associated to the rational and trigonometric $r$-matrices. A central result is the construction of a Poisson algebra associated to a non skew-symmetric $r$-matrix whose form is specified by a solution of the $N$-reflection equation. Generating functions of quantities in involution can be identified within this Poisson algebra. As an application, we construct new classical Gaudin-type Hamiltonians, particular cases of which are Gaudin Hamiltonians of $BC_L$-type .

Commentaires: 12 pages. References added. Explicit relation between our non-skew symmetric r-matrices and standard rational r-matrix given in the Gaudin models section

Ref HAL: hal-01820519_v1
Ref Arxiv: 1806.07748
DOI: 10.1088/1742-5468/aae2e0
WoS: WOS:000448440200001
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
5 Citations
Résumé:

Starting from the Bethe ansatz solution for the open Totally Asymmetric Simple Exclusion Process (TASEP), we compute the largest eigenvalue of the deformed Markovian matrix, in exact agreement with results obtained by the matrix ansatz. We also compute the eigenvalues of the higher conserved charges. The key step is to find a simpler equivalent T-Q relation, which is similar to the one for the TASEP with periodic boundary conditions.

Ref HAL: hal-01815115_v1
Ref Arxiv: 1805.08230
Ref INSPIRE: 1674353
DOI: 10.1103/PhysRevD.98.083533
WoS: 000448052300004
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
4 Citations
Résumé:

Assuming a simple form for the growth index γ(z) depending on two parameters γ0≡γ(z=0) and γ1≡γ′(z=0), we show that these parameters can be constrained using background expansion data. We explore systematically the preferred region in this parameter space. Inside general relativity we obtain that models with a quasistatic growth index and γ1≈-0.02 are favored. We find further the lower bounds γ0≳0.53 and γ1≳-0.15 for models inside GR. Models outside GR having the same background expansion as ΛCDM and arbitrary γ(z) with γ0=γ0ΛCDM, satisfy Geff,0>G for γ1>γ1ΛCDM, and Geff,0