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Author (up) Armillis, R.; Lazarides, G.; Pallis, C.
Title Inflation, leptogenesis, and Yukawa quasiunification within a supersymmetric left-right model Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 89 Issue 6 Pages 065032 - 22pp
Keywords
Abstract A simple extension of the minimal left-right symmetric supersymmetric grand unified theory model is constructed by adding two pairs of superfields. This naturally violates the partial Yukawa unification predicted by the minimal model. After including supergravity corrections, we find that this extended model naturally supports hilltop F-term hybrid inflation along its trivial inflationary path with only a very mild tuning of the initial conditions. With a convenient choice of signs of the terms in the Kahler potential, we can reconcile the inflationary scale with the supersymmetric grand unified theory scale. All the current data on the inflationary observables are readily reproduced. Inflation is followed by nonthermal leptogenesis via the decay of the right-handed neutrinos emerging from the decay of the inflaton, and any possible washout of the lepton asymmetry is avoided thanks to the violation of partial Yukawa unification. The extra superfields also assist us in reducing the reheat temperature so as to satisfy the gravitino constraint. The observed baryon asymmetry of the universe is naturally reproduced consistently with the neutrino oscillation parameters.
Address [Armillis, R.] Ecole Polytech Fed Lausanne, Inst Theorie Phenomenes Phys, CH-1015 Lausanne, Switzerland, Email: roberta.armillis@epfl.ch;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000334308100002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1760
Permanent link to this record
 
 
Author (up) Civiletti, M.; Pallis, C.; Shafi, Q.
Title Upper bound on the tensor-to-scalar ratio in GUT-scale supersymmetric hybrid inflation Type Journal Article
Year 2014 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 733 Issue Pages 276-282
Keywords
Abstract We explore the upper bound on the tensor-to-scalar ratio r in supersymmetric (F-term) hybrid inflation models with the gauge symmetry breaking scale set equal to the value 2.86 . 10(16) GeV, as dictated by the unification of the MSSM gauge couplings. We employ a unique renormalizable superpotential and a quasi-canonical Kahler potential, and the scalar spectral index n(s) is required to lie within the two-sigma interval from the central value found by the Planck satellite. In a sizable region of the parameter space the potential along the inflationary trajectory is a monotonically increasing function of the inflaton, and for this case, r less than or similar to 2.9.10(-4), while the spectral index running, vertical bar dn(s)/d ln k vertical bar, can be as large as 0.01. Ignoring higher order terms which ensure the boundedness of the potential for large values of the inflaton, the upper bound on r is significantly larger, of order 0.01, for subplanckian values of the inflaton, and vertical bar dn(s)/dlnk vertical bar similar or equal to 0.006.
Address [Civiletti, Matthew; Shafi, Qaisar] Univ Delaware, Dept Phys & Astron, Bartol Res Inst, Newark, DE 19716 USA, Email: mcivil@bartol.udel.edu;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000336430400048 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1805
Permanent link to this record
 
 
Author (up) Karagiannakis, N.; Lazarides, G.; Pallis, C.
Title Probing the hyperbolic branch/focus point region of the constrained minimal supersymmetric standard model with generalized Yukawa quasiunification Type Journal Article
Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 92 Issue 8 Pages 085018 - 15pp
Keywords
Abstract We analyze the parametric space of the constrained minimal supersymmetric standard model with μ> 0 supplemented by a generalized asymptotic Yukawa coupling quasiunification condition which yields acceptable masses for the fermions of the third family. We impose constraints from the cold dark matter abundance in the Universe and its direct-detection experiments, the B physics, as well as the masses of the sparticles and the lightest neutral CP-even Higgs boson. Fixing the mass of the latter to its central value from the LHC and taking 40 less than or similar to tan beta less than or similar to 50, we find a relatively wide allowed parameter space with -11 less than or similar to A(0)/M-1/2 less than or similar to 15 and a mass of the lightest sparticle in the range (0.09-1.1) TeV. This sparticle is possibly detectable by the present cold dark matter direct search experiments. The required fine-tuning for the electroweak symmetry breaking is much milder than the one needed in the neutralino-stau coannihilation region of the same model.
Address [Karagiannakis, N.; Lazarides, G.] Aristotle Univ Thessaloniki, Fac Engn, Sch Elect & Comp Engn, Thessaloniki 54124, Greece, Email: nikar@auth.gr;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000362901400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2417
Permanent link to this record
 
 
Author (up) Lazaries, G.; Pallis, C.
Title Shift symmetry and Higgs inflation in supergravity with observable gravitational waves Type Journal Article
Year 2015 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 114 - 28pp
Keywords Cosmology of Theories beyond the SM; Supergravity Models; Supersymmetric Effective Theories
Abstract We demonstrate how to realize within supergravity a novel chaotic-type inflationary scenario driven by the radial parts of a conjugate pair of Higgs superfields causing the spontaneous breaking of a grand unified gauge symmetry at a scale assuming the value of the supersymmetric grand unification scale. The superpotential is uniquely determined at the renormalizable level by the gauge symmetry and a continuous R symmetry. We select two types of Kahler potentials, which respect these symmetries as well as an approximate shift symmetry. In particular, they include in a logarithm a dominant shift-symmetric term proportional to a parameter c together with a small term violating this symmetry and characterized by a parameter c(+). In both cases, imposing a lower bound on c, inflation can be attained with subplanckian values of the original inflaton, while the corresponding effective theory respects perturbative unitarity for r +/- = c(+)/c_ <= 1. These inflationary models do not lead to overproduction of cosmic defects, are largely independent of the one-loop radiative corrections and accommodate, for natural values of r +/-, observable gravitational waves consistently with all the current observational data. The inflaton mass is mostly confined in the range (3.7 – 8.1) x 10(10) GeV.
Address [Lazaries, G.] Aristotle Univ Thessaloniki, Fac Engn, Sch Elect & Comp Engn, GR-54124 Thessaloniki, Greece, Email: lazaride@eng.auth.gr;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000365101200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2467
Permanent link to this record
 
 
Author (up) Pallis, C.
Title Kinetically modified nonminimal chaotic inflation Type Journal Article
Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 91 Issue 12 Pages 123508 - 6pp
Keywords
Abstract We consider supersymmetric (SUSY) and non-SUSY models of chaotic inflation based on the phi(n) potential with 2 <= n <= 6. We show that the coexistence of a nonminimal coupling to gravity f(R) = 1 + c(R)phi(n/2) with a kinetic mixing of the form f(K) = c(K)f(R)(m) can accommodate inflationary observables favored by the BICEP2/Keck Array and Planck results for 0 <= m <= 4 and 2.5 x 10(-4) <= r(RK) = c(R)/c(K)(n/4) <= 1, where the upper limit is not imposed for n 2. Inflation can be attained for sub-Planckian inflaton values with the corresponding effective theories retaining the perturbative unitarity up to the Planck scale.
Address [Pallis, Constantinos] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000355724600002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2249
Permanent link to this record
 
 
Author (up) Pallis, C.
Title Induced-gravity in inflation no-scale supergravity and beyond Type Journal Article
Year 2014 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 08 Issue 8 Pages 057 - 20pp
Keywords inflation; supersymmetry and cosmology
Abstract Supersymmetric versions of induced-gravity inflation are formulated within Supergravity (SUGRA) employing two gauge singlet chiral super fields. The proposed super-potential is uniquely determined by applying a continuous R and a discrete Z(n) symmetry. We select two types of logarithmic Kahler potentials, one associated with a no-scale-type SU(2, 1)/SU(2) x U(1)(R) x Z(n) Kahler manifold and one more generic. In both cases, imposing a lower bound on the parameter c R involved in the coupling between the inflaton and the Ricci scalar curvature – e.g. c(R) greater than or similar to 76, 105, 310 for n – 2, 3 and 6 respectively -, inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity. In the case of no-scale SUGRA we show that, for every n, the inflationary observables remain unchanged and in agreement with the current data while the inflaton mass is predicted to be 3 . 10(13) GeV. Beyond no-scale SUGRA the inflationary observables depend mildly on n and crucially on the coefficient involved in the fourth order term of the Kahler potential which mixes the inflaton with the accompanying non-inflaton field.
Address [Pallis, C.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: kpallis@gen.auth.gr
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000341848800057 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1944
Permanent link to this record
 
 
Author (up) Pallis, C.
Title Linking Starobinsky-type inflation in no-scale supergravity to MSSM Type Journal Article
Year 2014 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages 024 - 31pp
Keywords particle physics – cosmology connection; supersymmetry and cosmology; cosmology of theories beyond the SM; inflation
Abstract A novel realization of the Starobinsky inflationary model within a moderate extension of the Minimal Supersymmetric Standard Model (MSSM) is presented. The proposed superpotential is uniquely determined by applying a continuous R and a Z2 discrete symmetry, whereas the Kahler potential is associated with a no-scale-type SU(54, 1)/ SU(54) x U(1) R X Z2 Kahler manifold. The inflaton is identified with a Higgs-like modulus whose the vacuum expectation value controls the gravitational strength. Thanks to a strong enough coupling (with a parameter CT involved) between the inflaton and the Ricci scalar curvature, inflation can be attained even for subplanckian values of the inflaton with CT >= 76 and the corresponding effective theory being valid up to the Planck scale. The inflationary observables turn out to be in agreement with the current data and the inflaton mass is predicted to be 3 10(3) GeV. At the cost of a relatively small superpotential coupling constant, the model offers also a resolution of the f,t problem of MSSM for CT <= 4500 and gravitino heavier than about 10(4) GeV. Supplementing MSSM by three right-handed neutrinos we show that spontaneously arising couplings between the inflaton and the particle content of MSSM not only ensure a sufficiently low reheating temperature but also support a scenario of non-thermal leptogenesis consistently with the neutrino oscillation parameters.
Address [Pallis, C.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: kpallis@auth.gr
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000343042800006 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1961
Permanent link to this record
 
 
Author (up) Pallis, C.
Title Reconciling induced-gravity inflation in supergravity with the Planck 2013 & BICEP2 results Type Journal Article
Year 2014 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 10 Issue 10 Pages 058 - 18pp
Keywords supersymmetry and cosmology; inflation; modified gravity
Abstract We generalize the embedding of induced-gravity inflation beyond the no-scale Supergravity presented in ref. [1] employing two gauge singlet chiral superfields, a superpotential uniquely determined by applying a continuous R and a discrete Z(n) symmetries, and a logarithmic Kahler potential including all the allowed terms up to fourth order in powers of the various fields. We show that, increasing slightly the prefactor (-3) encountered in the adopted Kahler potential, an efficient enhancement of the resulting tensor-to-scalar ratio can be achieved rendering the predictions of the model consistent with the recent BICEP2 results, even with subplanckian excursions of the original inflaton field. The remaining inflationary observables can become compatible with the data by mildly tuning the coefficient involved in the fourth order term of the Kahler potential which mixes the inflaton with the accompanying non-inflaton field. The inflaton mass is predicted to be close to 10(14) GeV.
Address [Pallis, C.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: kpallis@auth.gr
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000345990800059 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2043
Permanent link to this record
 
 
Author (up) Pallis, C.; Shafi, Q.
Title Gravity waves from non-minimal quadratic inflation Type Journal Article
Year 2015 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 03 Issue 3 Pages 023 - 31pp
Keywords inflation; supersymmetry and cosmology; cosmology of theories beyond the SM
Abstract We discuss non-minimal quadratic inflation in supersymmetric (SUSY) and non-SUSY models which entails a linear coupling of the inflaton to gravity. Imposing a lower bound on the parameter c(R), involved in the coupling between the inflaton and the Ricci scalar curvature, inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity up to the Planck scale. Working in the non-SUSY context we also consider radiative corrections to the inflationary potential due to a possible coupling of the inflaton to bosons or fermions. We find ranges of the parameters, depending mildly on the renormalization scale, with adjustable values of the spectral index n(s), tensor-to-scalar ratio r similar or equal to (2 – 4) . 10(-3), and an inflaton mass close to 3 . 10 (13) GeV. In the SUSY framework we employ two gauge singlet chiral superfields, a logarithmic Kahler potential including all the allowed terms up to fourth order in powers of the various fields, and determine uniquely the superpotential by applying a continuous R and a global U(1) symmetry. When the Kahler manifold exhibits a no-scale-type symmetry, the model predicts n(s) similar or equal to 0.963 and r similar or equal to 0.004. Beyond no-scale SUGRA, n(s) and r depend crucially on the coefficient involved in the fourth order term, which mixes the inflaton with the accompanying non-inflaton field in the Kahler potential, and the prefactor encountered in it. Increasing slightly the latter above (-3), an efficient enhancement of the resulting r can be achieved putting it in the observable range. The inflaton mass in the last case is confined in the range (5 – 9) . 10(13) GeV.
Address [Pallis, Constantinos] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: cpallis@ific.uv.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000355633800023 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2263
Permanent link to this record
 
 
Author (up) Pallis, C.; Shafi, Q.
Title From hybrid to quadratic inflation with high-scale supersymmetry breaking Type Journal Article
Year 2014 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 736 Issue Pages 261-266
Keywords
Abstract Motivated by the reported discovery of inflationary gravity waves by the BICEP2 experiment, we propose an inflationary scenario in supergravity, based on the standard superpotential used in hybrid inflation. The new model yields a tensor-to-scalar ratio r similar or equal to 0.14 and scalar spectral index n(s) similar or equal to 0.964, corresponding to quadratic (chaotic) inflation. The important new ingredients are the high-scale, (1.6-10) . 10(13) GeV, soft supersymmetry breaking mass for the gauge singlet inflaton field and a shift symmetry imposed on the Kahler potential. The end of inflation is accompanied, as in the earlier hybrid inflation models, by the breaking of a gauge symmetry at (1.2-7.1) . 10(16) GeV, comparable to the grand-unification scale.
Address [Pallis, Constantinos] Univ Valencia, CSIC, IFIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: cpallis@ific.uv.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000341487800036 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1938
Permanent link to this record