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Diffeomorphic deformable image registration is one of the crucial tasks in medical image analysis, which aims to find a unique transformation while preserving the topology and invertibility of the transformation. Deep convolutional neural…

Image and Video Processing · Electrical Eng. & Systems 2022-02-09 Ameneh Sheikhjafari , Michelle Noga , Kumaradevan Punithakumar , Nilanjan Ray

In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in $f(R)$ framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-12 Nareg Mirzatuny , Shahram Khosravi , Shant Baghram , Hossein Moshafi

We investigate the evolution of a spatially flat Friedmann-Robertson-Walker (FRW) universe in the framework of scalar non-metricity theory of gravity. In the model, we consider dark matter (DM) and dark energy (DE) described by the scalar…

General Relativity and Quantum Cosmology · Physics 2025-08-05 Bikash Chandra Roy , Bikash Chandra Paul

Even if the fundamental action of gravity is local, the corresponding quantum effective action, that includes the effect of quantum fluctuations, is a nonlocal object. These nonlocalities are well understood in the ultraviolet regime but…

High Energy Physics - Theory · Physics 2018-03-21 Enis Belgacem , Yves Dirian , Stefano Foffa , Michele Maggiore

We investigate the evolution of matter density perturbations within a fractional cosmological framework inspired by fractal space-time constructions in field theory, where a deformation of the integration measure induces non-locality and…

General Relativity and Quantum Cosmology · Physics 2026-04-24 S. M. M. Rasouli

Recent analyses \cite{Nesseris:2017vor,Kazantzidis:2018rnb} have indicated that an effective Newton's constant $G_{\rm eff}(z)$ decreasing with redshift may relieve the observed tension between the Planck15 best fit $\Lambda$CDM…

General Relativity and Quantum Cosmology · Physics 2018-12-05 Radouane Gannouji , Lavrentios Kazantzidis , Leandros Perivolaropoulos , David Polarski

Bimetric gravity is an interesting alternative to standard GR given its potential to provide a concrete theoretical framework for a ghost-free massive gravity theory. Here we investigate a class of Bimetric gravity models for their…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Ajay Bassi , Shahnawaz A. Adil , Manvendra Pratap Rajvanshi , Anjan A. Sen

We study structure formation in phenomenological models in which the Friedmann equation receives a correction of the form $H^{\alpha}/r_c^{2-\alpha}$, which realize an accelerated expansion without dark energy. In order to address structure…

Astrophysics · Physics 2009-11-11 Kazuya Koyama

In this paper, we study the gravitational lensing around the static and spherically symmetric DD black holes, which we recently derived as perturbations of the Schwarzschild geometry within the revised Deser-Woodard theory of nonlocal…

General Relativity and Quantum Cosmology · Physics 2026-04-16 Rocco D'Agostino , Vittorio De Falco

We investigate the ability of state-of-the-art redshift-space distortions models for the galaxy anisotropic two-point correlation function \xi(r_p, \pi), to recover precise and unbiased estimates of the linear growth rate of structure f,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Sylvain de la Torre , Luigi Guzzo

In the context of $f(\mathcal{R})$ gravity, dark energy is a geometrical fluid with negative equation of state. Since the function $f(\mathcal{R})$ is not known \emph{a priori}, the need of a model independent reconstruction of its shape…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Salvatore Capozziello , Mariafelicia De Laurentis , Orlando Luongo

For conformally invariant gravity theories defined on Riemannian spacetime and having the Schwarzschild--de-Sitter (SdS) metric as a solution in the Einstein gauge, we consider whether one may conformally rescale this solution to obtain…

General Relativity and Quantum Cosmology · Physics 2022-07-13 Michael Hobson , Anthony Lasenby

We have previously presented a reconstruction of Horndeski scalar-tensor theories from linear cosmological observables. It includes free nonlinear terms which can be added onto the reconstructed covariant theory without affecting the…

General Relativity and Quantum Cosmology · Physics 2019-08-21 Joe Kennedy , Lucas Lombriser , Andy Taylor

Matter evolved under influence of gravity from minuscule density fluctuations. Non-perturbative structure formed hierarchically over all scales, and developed non-Gaussian features in the Universe, known as the Cosmic Web. To fully…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-01 Siyu He , Yin Li , Yu Feng , Shirley Ho , Siamak Ravanbakhsh , Wei Chen , Barnabás Póczos

We revisit a cosmological model where dark matter (DM) and dark energy (DE) follow barotropic equations of state, allowing deviations from the standard $\Lambda$CDM framework (i.e. $w_{dm} \neq 0$, $w_{de} \neq -1$), considering both flat…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Dorian Araya , Cristian Castillo , Genly Leon , Juan Magaña , Angie Barr Domínguez , Miguel A. García-Aspeitia

In this paper, we study the non-linear matter power spectrum in a specific family of $f(R)$ models that can reproduce the $\Lambda$CDM background expansion history, using high resolution $N$-body simulations based on the {\sc ecosmog} code.…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-13 Jian-hua He , Baojiu Li , Yipeng Jing

In this paper, we propose a learning-based framework for non-rigid shape registration without correspondence supervision. Traditional shape registration techniques typically rely on correspondences induced by extrinsic proximity, therefore…

Computer Vision and Pattern Recognition · Computer Science 2023-11-09 Puhua Jiang , Mingze Sun , Ruqi Huang

We use large volume N-body simulations to predict the clustering of dark matter in redshift space in f(R) modified gravity cosmologies. This is the first time that the nonlinear matter and velocity fields have been resolved to such a high…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-24 Elise Jennings , Carlton M. Baugh , Baojiu Li , Gong-Bo Zhao , Kazuya Koyama

This paper is concerned with theories of gravity that contain a scalar coupled both conformally and disformally to matter through the metric. By systematically deriving the non-relativistic limit, it is shown that no new non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Jeremy Sakstein

Stage IV large scale structure surveys are promising probes of gravity on cosmological scales. Due to the vast model-space in the modified gravity literature, model-independent parameterisations represent useful and scalable ways to test…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-03 Sankarshana Srinivasan , Daniel B Thomas , Peter L. Taylor
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