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Hans Peter Nilles

Bio: Hans Peter Nilles is an academic researcher from University of Bonn. The author has contributed to research in topics: Supersymmetry & Heterotic string theory. The author has an hindex of 52, co-authored 167 publications receiving 13547 citations. Previous affiliations of Hans Peter Nilles include University of Geneva & Technische Universität München.


Papers
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TL;DR: In this paper, a short introduction to N = 1 supersymmetry and supergravity and review the attempts to construct models in which the breakdown scale of the weak interactions is related to supersymmetric breaking is given.

3,056 citations

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TL;DR: In this paper, the authors proposed a mechanism which provides an effective large axion scale, although the original one is sub-Planckian, based on the presence of two axions, with a potential provided by two anomalous gauge groups.
Abstract: If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation, requires an axion scale which is greater than the (reduced) Planck scale. It is unclear whether such a high value is compatible with an effective field theoretical description, and whether the global axionic symmetry survives quantum gravity effects. We propose a mechanism which provides an effective large axion scale, although the original one is sub-Planckian. The mechanism is based on the presence of two axions, with a potential provided by two anomalous gauge groups. The effective large axion scale is due to an almost exact symmetry between the couplings of the axions to the anomalous groups. We also comment on a possible implementation in heterotic string theory.

586 citations

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TL;DR: In this paper, the structure of soft supersymmetry breaking terms in KKLT models of flux compactification with low energy supersymmetric terms was examined and the modulus mediation is comparable to the anomaly mediation, yielding a quite distinctive sparticle spectrum.

545 citations

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TL;DR: In this paper, it was shown that spontaneously broken N = 1 supergravity can lead to an effective low-energy theory which is phenomenologically acceptable, and the naturalness condition that the low energy superpotential be scale invariant is imposed.

488 citations

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TL;DR: In this paper, the consequences of the presence of gauge background fields on the torus underlying the Z-orbifold compactification of the heterotic string were studied, and it was pointed out that such Wilson lines provide a mechanism for controlling the number of chiral matter states both from twisted and untwisted sectors, as well as breaking the symmetry group.

435 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal ArticleDOI
Claude Amsler1, Michael Doser2, Mario Antonelli, D. M. Asner3  +173 moreInstitutions (86)
TL;DR: This biennial Review summarizes much of particle physics, using data from previous editions.

12,798 citations

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TL;DR: In this article, the authors review the observational evidence for the current accelerated expansion of the universe and present a number of dark energy models in addition to the conventional cosmological constant, paying particular attention to scalar field models such as quintessence, K-essence and tachyon.
Abstract: We review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating universe. In particular we discuss the arguments for and recent progress made towards understanding the nature of dark energy. We review the observational evidence for the current accelerated expansion of the universe and present a number of dark energy models in addition to the conventional cosmological constant, paying particular attention to scalar field models such as quintessence, K-essence, tachyon, phantom and dilatonic models. The importance of cosmological scaling solutions is emphasized when studying the dynamical system of scalar fields including coupled dark energy. We study the evolution of cosmological perturbations allowing us to confront them with the observation of the Cosmic Microwave Background and Large Scale Structure and demonstrate how it is possible in principle to reconstruct the equation of state of dark energy by also using Supernovae Ia observational data. We also discuss in detail the nature of tracking solutions in cosmology, particle physics and braneworld models of dark energy, the nature of possible future singularities, the effect of higher order curvature terms to avoid a Big Rip singularity, and approaches to modifying gravity which leads to a late-time accelerated expansion without recourse to a new form of dark energy.

5,954 citations

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TL;DR: A comprehensive survey of recent work on modified theories of gravity and their cosmological consequences can be found in this article, where the authors provide a reference tool for researchers and students in cosmology and gravitational physics, as well as a selfcontained, comprehensive and up-to-date introduction to the subject as a whole.

3,674 citations

Journal ArticleDOI
Peter A. R. Ade, Nabila Aghanim, Monique Arnaud, Frederico Arroja, M. Ashdown, J. Aumont, Carlo Baccigalupi, Mario Ballardini, A. J. Banday, R. B. Barreiro, Nicola Bartolo, E. Battaner, K. Benabed, Alain Benoit, A. Benoit-Lévy, J.-P. Bernard, Marco Bersanelli, P. Bielewicz, J. J. Bock, Anna Bonaldi, Laura Bonavera, J. R. Bond, Julian Borrill, François R. Bouchet, F. Boulanger, M. Bucher, Carlo Burigana, R. C. Butler, Erminia Calabrese, Jean-François Cardoso, A. Catalano, Anthony Challinor, A. Chamballu, R.-R. Chary, H. C. Chiang, P. R. Christensen, Sarah E. Church, David L. Clements, S. Colombi, L. P. L. Colombo, C. Combet, D. Contreras, F. Couchot, A. Coulais, B. P. Crill, A. Curto, F. Cuttaia, Luigi Danese, R. D. Davies, R. J. Davis, P. de Bernardis, A. de Rosa, G. de Zotti, Jacques Delabrouille, F.-X. Désert, Jose M. Diego, H. Dole, S. Donzelli, Olivier Doré, Marian Douspis, A. Ducout, X. Dupac, George Efstathiou, F. Elsner, Torsten A. Ensslin, H. K. Eriksen, James R. Fergusson, Fabio Finelli, Olivier Forni, M. Frailis, Aurelien A. Fraisse, E. Franceschi, A. Frejsel, Andrei V. Frolov, S. Galeotta, Silvia Galli, K. Ganga, C. Gauthier, M. Giard, Y. Giraud-Héraud, E. Gjerløw, J. González-Nuevo, Krzysztof M. Gorski, Serge Gratton, A. Gregorio, Alessandro Gruppuso, Jon E. Gudmundsson, Jan Hamann, Will Handley, F. K. Hansen, Duncan Hanson, D. L. Harrison, Sophie Henrot-Versille, C. Hernández-Monteagudo, D. Herranz, S. R. Hildebrandt, E. Hivon, Michael P. Hobson, W. A. Holmes 
TL;DR: In this article, the authors report on the implications for cosmic inflation of the 2018 Release of the Planck CMB anisotropy measurements, which are fully consistent with the two previous Planck cosmological releases, but have smaller uncertainties thanks to improvements in the characterization of polarization at low and high multipoles.
Abstract: We report on the implications for cosmic inflation of the 2018 Release of the Planck CMB anisotropy measurements. The results are fully consistent with the two previous Planck cosmological releases, but have smaller uncertainties thanks to improvements in the characterization of polarization at low and high multipoles. Planck temperature, polarization, and lensing data determine the spectral index of scalar perturbations to be $n_\mathrm{s}=0.9649\pm 0.0042$ at 68% CL and show no evidence for a scale dependence of $n_\mathrm{s}.$ Spatial flatness is confirmed at a precision of 0.4% at 95% CL with the combination with BAO data. The Planck 95% CL upper limit on the tensor-to-scalar ratio, $r_{0.002}<0.10$, is further tightened by combining with the BICEP2/Keck Array BK15 data to obtain $r_{0.002}<0.056$. In the framework of single-field inflationary models with Einstein gravity, these results imply that: (a) slow-roll models with a concave potential, $V" (\phi) < 0,$ are increasingly favoured by the data; and (b) two different methods for reconstructing the inflaton potential find no evidence for dynamics beyond slow roll. Non-parametric reconstructions of the primordial power spectrum consistently confirm a pure power law. A complementary analysis also finds no evidence for theoretically motivated parameterized features in the Planck power spectrum, a result further strengthened for certain oscillatory models by a new combined analysis that includes Planck bispectrum data. The new Planck polarization data provide a stringent test of the adiabaticity of the initial conditions. The polarization data also provide improved constraints on inflationary models that predict a small statistically anisotropic quadrupolar modulation of the primordial fluctuations. However, the polarization data do not confirm physical models for a scale-dependent dipolar modulation.

3,438 citations