9,705 research outputs found

    Inflation with Holographic Dark Energy

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    We investigate the corrections of the holographic dark energy to inflation paradigm. We study the evolution of the holographic dark energy in the inflationary universe in detail, and carry out a model-independent analysis on the holographic dark energy correction to the primordial scalar power spectrum. It turns out that the corrections generically make the spectrum redder. To be consistent with the experimental data, there must be a upper bound on the reheating temperature. We also discuss the corrections due to different choices of the infrared cutoff.Comment: 15 pages, 3 figures, v2: references added, a fast-roll discussion added. v3: typos corrected. v4: final version to appear in NP

    Inflationary NonGaussianity from Thermal Fluctuations

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    We calculate the contribution of the fluctuations with the thermal origin to the inflationary nonGaussianity. We find that even a small component of radiation can lead to a large nonGaussianity. We show that this thermal nonGaussianity always has positive fNLf_{\rm NL}. We illustrate our result in the chain inflation model and the very weakly dissipative warm inflation model. We show that fNL∼O(1)f_{NL}\sim {\cal O}(1) is general in such models. If we allow modified equation of state, or some decoupling effects, the large thermal nonGaussianity of order fNL>5f_{\rm NL}>5 or even fNL∼100f_{\rm NL}\sim 100 can be produced. We also show that the power spectrum of chain inflation should have a thermal origin. In the Appendix A, we made a clarification on the different conventions used in the literature related to the calculation of fNLf_{\rm NL}.Comment: 20 pages, 1 figure. v2, v3: references and acknowledgments update

    Uniqueness theorems for meromorphic mappings sharing hyperplanes in general position

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    The purpose of this article is to study the uniqueness problem for meromorphic mappings from Cn\mathbb{C}^{n} into the complex projective space PN(C).\mathbb{P}^{N}(\mathbb{C}). By making using of the method of dealing with multiple values due to L. Yang and the technique of Dethloff-Quang-Tan respectively, we obtain two general uniqueness theorems which improve and extend some known results of meromorphic mappings sharing hyperplanes in general position.Comment: 10 page

    Generalized Space-time Noncommutative Inflation

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    We study the noncommutative inflation with a time-dependent noncommutativity between space and time. From the numerical analysis of power law inflation, there are clues that the CMB spectrum indicates a nonconstant noncommutative inflation. Then we extend our treatment to the inflation models with more general noncommutativity and find that the scalar perturbation power spectrum depends sensitively on the time varying of the spacetime noncommutativity. This stringy effect may be probed in the future cosmological observations.Comment: 15 pages, 2 figure
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