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We show how observations of the perturbation spectra produced during inflation may be used to constrain the parameters of general scalar-tensor theories of gravity, which include both an inflaton and dilaton field. An interesting feature of…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Juan Garcia-Bellido , David Wands

Robustness of the solutions to the inflaton potential inverse problem based on the slow-roll approximation is addressed. With that aim it is introduced a measure of the difference of the outputs obtained using first and second order…

Astrophysics · Physics 2009-11-13 H. P. de Oliveira , C. A. Terrero-Escalante

We show that the inference problem of constraining the dipole amplitude with inclusive deep inelastic scattering data can be written into a discrete linear inverse problem, in an analogous manner as can be done for computed tomography. To…

High Energy Physics - Phenomenology · Physics 2025-11-20 Henri Hänninen , Antti Kykkänen , Hjørdis Schlüter

We calculate the power spectrum of curvature perturbations when the inflaton field is rolling over the top of a local maximum of a potential. We show that the evolution of the field can be decomposed into a late-time attractor, which is…

Astrophysics · Physics 2008-11-26 Konstantinos Tzirakis , William H. Kinney

In this paper, we consider several geometric inverse problems for linear elliptic systems. We prove uniqueness and stability results. In particular, we show the way that the observation depends on the perturbations of the domain. In some…

Analysis of PDEs · Mathematics 2024-02-02 Raul K. C. Araújo , Enrique Fernández-Cara , Diego A. Souza

The inverse spectral problem is solved for the class of Sturm-Liouville operators with singular real-valued potentials from the space $W^{-1}_2(0,1)$. The potential is recovered via the eigenvalues and the corresponding norming constants.…

Spectral Theory · Mathematics 2007-05-23 R. O. Hryniv , Ya. V. Mykytyuk

If primordial scalar and tensor perturbation spectra can be inferred from observations of the cosmic background radiation and large-scale structure, then one might hope to reconstruct a unique single-field inflaton potential capable of…

Astrophysics · Physics 2016-08-25 Edmund J. Copeland , Ian J. Grivell , Edward W. Kolb , Andrew R. Liddle

Inverse scattering transform method of the heat equation is developed for a special subclass of potentials nondecaying at space infinity---perturbations of the one-soliton potential by means of decaying two-dimensional functions. Extended…

Exactly Solvable and Integrable Systems · Physics 2009-11-07 M. Boiti , F. Pempinelli , A. K. Pogrebkov , B. Prinari

We describe a method of obtaining the inflationary potential from observations which does not use the slow-roll approximation. Rather, the microwave anisotropy spectrum is obtained directly from a parametrized potential numerically, with no…

Astrophysics · Physics 2009-12-30 Ian J Grivell , Andrew R Liddle

A perturbative strategy for inflation described by two-inflaton fields is developed using a mathematical analogy with the renormalization-group. Two small quantities, $\alpha$ and $\lambda$, corresponding to standard slow-roll parameters…

High Energy Physics - Theory · Physics 2025-06-10 Bohdan Grzadkowski , Marco Piva

This article is devoted to the study of scalar perturbations in loop quantum cosmology. It aims at clarifying the situation with respect to the way initial conditions are set and to the specific choice of an inflaton potential. Several…

General Relativity and Quantum Cosmology · Physics 2018-10-10 Aurélien Barrau , Pierre Jamet , Killian Martineau , Flora Moulin

We propose a single field inflationary model by generalizing the inverse power law potential from the intermediate model. We study the implication of our model on the primordial anisotropy of cosmological microwave background radiation.…

High Energy Physics - Theory · Physics 2015-06-17 Zhun Lu

The observational data on the anisotropy of the cosmic microwave background constraints the scalar spectral tilt $n_s$ and the tensor to scalar ratio $r$ which depend on the first and second derivatives of the inflaton potential. The…

General Relativity and Quantum Cosmology · Physics 2016-05-20 Jianmang Lin , Qing Gao , Yungui Gong

An inverse scattering method based on an auxiliary inverse Sturm-Liouville problem recently proposed by Horv\'ath and Apagyi [Mod. Phys. Lett. B 22, 2137 (2008)] is examined in various aspects and developed further to (re)construct…

Mathematical Physics · Physics 2012-09-21 Tamas Palmai , Barnabas Apagyi

In this work the LHC inverse problem is quantified in the Bayesian context by clarifying the relation between the mapping from the theory parameter space to experimental signature space and the inverse map. We demonstrate that, after…

High Energy Physics - Phenomenology · Physics 2015-05-13 Csaba Balázs , Dilani Kahawala

Inflationary cosmology provides a successful paradigm for solving several problems, notably the generation of density perturbations which seed the formation of observed cosmic structure. We show how to use inverse scattering theory as the…

Astrophysics · Physics 2009-11-10 Salman Habib , Katrin Heitmann , Gerard Jungman

A condition, at which the one-dimensional inverse power potential becomes reflectionless during propagation through it of a plane wave, is obtained on the basis of SUSY QM methods. A scattering of a particle on spherically symmetric inverse…

Quantum Physics · Physics 2007-05-23 Sergei P. Maydanyuk

Recent observations suggest that the spectral index of the primordial perturbations is very close to unity, as expected in models of slow roll inflation. It is still possible for such models to produce spectra which are scale dependent. We…

Astrophysics · Physics 2009-09-02 Scott Dodelson , Ewan Stewart

We find that the amplitude of quantum fluctuations of the invariant de Sitter vacuum coincides exactly with that of the vacuum of a comoving observer for a massless scalar (inflaton) field. We propose redefining the actual physical power…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

In this study, the theorem on necessary and sufficient conditions for the solvability of inverse problem for Sturm-Liouville operator with discontinuous coefficient is proved and the algorithm of reconstruction of potential from spectral…

Spectral Theory · Mathematics 2016-04-21 Döne Karahan , Khanlar. R. Mamedov