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相关论文: Observational Constraints in Nonlocal Gravity: the…

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In this work, we extend previous analyses of the structure formation in the $f(\Box^{-1}R)$ model of nonlocal gravity proposed by Deser and Woodard (DW), which reproduces the background expansion of $\Lambda$CDM with no need of a…

宇宙学与河外天体物理 · 物理学 2017-05-03 Henrik Nersisyan , Adrian Fernandez Cid , Luca Amendola

Alternative cosmological models have been under deep scrutiny in recent years, aiming to address the main shortcomings of the $\Lambda$CDM model. Moreover, as the accuracy of cosmological surveys improved, new tensions have risen between…

宇宙学与河外天体物理 · 物理学 2023-01-05 Filippo Bouchè , Salvatore Capozziello , Vincenzo Salzano

We examine the origin of two opposite results for the growth of perturbations in the Deser-Woodard (DW) nonlocal gravity model. One group previously analyzed the model in its original nonlocal form and showed that the growth of structure in…

广义相对论与量子宇宙学 · 物理学 2018-02-14 Sohyun Park

We consider the structure formation in the nonlocal gravity model proposed recently by Deser and Woodard (DW-2019 model), which can not only reproduce the $\Lambda$CDM cosmology without fine-tuning puzzle but also may provide a screening…

宇宙学与河外天体物理 · 物理学 2019-12-20 Jia-Cheng Ding , Jian-Bo Deng

We discuss a modified gravity model which fits cosmological observations at a level statistically indistinguishable from $\Lambda$CDM and at the same time predicts very large deviations from General Relativity (GR) in the propagation of…

宇宙学与河外天体物理 · 物理学 2019-11-27 Enis Belgacem , Yves Dirian , Andreas Finke , Stefano Foffa , Michele Maggiore

The Deser-Woodard (DW) nonlocal gravity model has been proposed in order to describe the late-time acceleration of the universe without introducing dark energy. In this paper we focus, however, on the early stage of the universe and…

广义相对论与量子宇宙学 · 物理学 2019-07-22 Che-Yu Chen , Pisin Chen , Sohyun Park

The observed acceleration of the Universe can be explained by modifying general relativity. One such attempt is the nonlocal model of Deser and Woodard. Here we fix the background cosmology using results from the Planck satellite and…

宇宙学与河外天体物理 · 物理学 2014-09-05 Scott Dodelson , Sohyun Park

We study the cosmological consequences of a recently proposed nonlocal modification of general relativity, obtained by adding a term $m^2R\,\Box^{-2}R$ to the Einstein-Hilbert action. The model has the same number of parameters as…

宇宙学与河外天体物理 · 物理学 2014-07-16 Yves Dirian , Stefano Foffa , Nima Khosravi , Martin Kunz , Michele Maggiore

We investigate the gravitational lensing effects of a static spherically symmetric black hole (BH) within the framework of the revised Deser-Woodard (D-W) nonlocal gravity. By analyzing the deflection angle in both the weak and strong field…

广义相对论与量子宇宙学 · 物理学 2026-01-26 Haida Li , Xiangdong Zhang

We propose a simple, nonlocal modification to general relativity (GR) on large scales, which provides a model of late-time cosmic acceleration in the absence of the cosmological constant and with the same number of free parameters as in…

广义相对论与量子宇宙学 · 物理学 2018-03-30 Valeri Vardanyan , Yashar Akrami , Luca Amendola , Alessandra Silvestri

We re-analyze the nonlocal gravity model of Deser and Woodard which was proposed to account for the current phase of cosmic acceleration. We show that the growth of perturbations predicted by this nonlocal gravity model when its background…

宇宙学与河外天体物理 · 物理学 2017-04-05 Sohyun Park , Arman Shafieloo

We provide a systematic and updated discussion of a research line carried out by our group over the last few years, in which gravity is modified at cosmological distances by the introduction of nonlocal terms, assumed to emerge at an…

宇宙学与河外天体物理 · 物理学 2020-04-15 Enis Belgacem , Yves Dirian , Andreas Finke , Stefano Foffa , Michele Maggiore

In this work, we analyzed the improved Deser-Woodard non-local gravity over the background of five different bouncing cosmologies, whose premise is avoid the initial singular state of the universe. We developed the numerical solution for…

广义相对论与量子宇宙学 · 物理学 2022-06-01 D. Jackson , R. Bufalo

Inspired by an exponential $f(R)$ gravity model studied in the literature, in this work we introduce a new and viable $f(Q)$ gravity model, which can be represented as a perturbation of $\Lambda$CDM. Typically, within the realm of $f(Q)$…

宇宙学与河外天体物理 · 物理学 2024-01-31 A. Oliveros , Mario A. Acero

We use the cosmic shear data from the Canada-France-Hawaii Telescope Lensing Survey to place constraints on $f(R)$ and {\it Generalized Dilaton} models of modified gravity. This is highly complimentary to other probes since the constraints…

宇宙学与河外天体物理 · 物理学 2015-10-21 Joachim Harnois-Déraps , Dipak Munshi , Patrick Valageas , Ludovic van Waerbeke , Philippe Brax , Peter Coles , Luca Rizzo

We present constraints on modified gravity from a cosmic shear analysis of the final data release of the Kilo-Degree Survey (KiDS-Legacy) in combination with DESI measurements of baryon acoustic oscillations, eBOSS observations of redshift…

New corrections to General Relativity are considered in the context of modified $f(R)$ gravity, that satisfy cosmological and local gravity constraints. The proposed models behave asymptotically as $R-2\Lambda$ at large curvature and show…

广义相对论与量子宇宙学 · 物理学 2022-01-13 L. N. Granda

This thesis explores the cosmological implications of modified gravity, focusing on nonmetricity-based $f(Q)$ gravity as an alternative to the $\Lambda$CDM model in explaining cosmic acceleration. Chapter I lays the theoretical groundwork…

广义相对论与量子宇宙学 · 物理学 2025-04-15 Gaurav N. Gadbail

One way to account for the acceleration of the universe is to modify general relativity, rather than introducing dark energy. Typically, such modifications introduce new degrees of freedom. It is interesting to consider models with no new…

天体物理学 · 物理学 2011-05-12 Sean M. Carroll , Ignacy Sawicki , Alessandra Silvestri , Mark Trodden

Modified gravity (MG) theories predict, in general, that the ratio of gravitational wave (GW) to electromagnetic (EM) luminosity distances, $\Xi$, differs from its general relativity (GR) value of unity at cosmological scales, thus…

广义相对论与量子宇宙学 · 物理学 2021-05-28 Isabela S. Matos , Maurício O. Calvão , Ioav Waga
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