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We derive exact traversable wormhole solutions in the framework of $f(R)$ gravity with no exotic matter and with stable conditions over the geometric fluid entering the throat. For this purpose, we propose power-law $f(R)$ models and two…

General Relativity and Quantum Cosmology · Physics 2020-12-29 Salvatore Capozziello , Orlando Luongo , Lorenza Mauro

We consider the problem of finding approximate analytical solutions for nonlinear equations typical of physics applications. The emphasis is on the modification of the method of Pad\'e approximants that are known to provide the best…

Mathematical Physics · Physics 2020-04-01 S. Gluzman , V. I. Yukalov

Traversability in relation with tides across thin-shell wormholes is analyzed. Conditions for a safe travel through a wormhole throat are established in terms of the parameters characterizing the geometries and reasonable assumptions…

General Relativity and Quantum Cosmology · Physics 2021-11-02 E. Rubín de Celis , C. Simeone

In this paper, we explore wormhole solutions in a higher-derivative theory of gravity where the action depends not only on the Ricci scalar \(R\), but also on its d'Alembertian, \(\Box R\). Such \(f(R,\Box R)\) models are motivated by…

General Relativity and Quantum Cosmology · Physics 2026-05-19 M Daniel Ranjan , Soumya Chakrabarti , Sanjit Das

The evaluation of robustness and reliability of realistic structures in the presence of uncertainty involves costly numerical simulations with a very high number of evaluations. This motivates model order reduction techniques like the…

Numerical Analysis · Mathematics 2024-12-20 Steffen Kastian , Dieter Moser , Stefanie Reese , Lars Grasedyck

Recent studies have shown that (a) quantum effects may be sufficient to support a wormhole throat and (b) the total amount of "exotic matter" can be made arbitrarily small. Unfortunately, using only small amounts of exotic matter may result…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Peter K. F. Kuhfittig

We study the traversable wormhole solutions for a logarithmic corrected $f(R)$ model by considering two different statements of shape $b(r)$ and redshift $\Phi(r)$ functions. We calculate the parameters of the model including energy density…

General Relativity and Quantum Cosmology · Physics 2022-03-29 J. Sadeghi , M. Shokri , S. Noori Gashti , B. Pourhassan , P. Rudra

Most distinguishing features of black holes and their mimickers are concentrated near the horizon. In contrast, astrophysical observations and theoretical considerations primarily constrain the far-field geometry. In this work we develop…

General Relativity and Quantum Cosmology · Physics 2025-12-10 Swayamsiddha Maharana , Fil Simovic , Ioannis Soranidis , Daniel R. Terno

It was shown by Ford and Roman in 1996 that quantum field theory severely constrains wormhole geometries on a macroscopic scale. The first part of this paper discusses a wide class of wormhole solutions that meet these constraints. The type…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Peter K. F. Kuhfittig

Motivated by recent proposals of possible wormhole shape functions, we construct a wormhole shape function by employing the Karmarkar condition for static traversable wormhole geometry. The proposed shape function generates wormhole…

General Relativity and Quantum Cosmology · Physics 2020-12-07 M. Farasat Shamir , I. Fayyaz

The present work deals with the rational model order reduction method based on the single-point Least-Square (LS) Pad\'e approximation technique introduced in [3]. Algorithmical aspects concerning the construction of the rational LS-Pad\'e…

Numerical Analysis · Mathematics 2018-06-08 Francesca Bonizzoni , Fabio Nobile , Ilaria Perugia , Davide Pradovera

POD-DL-ROMs have been recently proposed as an extremely versatile strategy to build accurate and reliable reduced order models (ROMs) for nonlinear parametrized partial differential equations, combining (i) a preliminary dimensionality…

Numerical Analysis · Mathematics 2023-05-09 Simone Brivio , Stefania Fresca , Nicola Rares Franco , Andrea Manzoni

We consider a framework for the construction of iterative schemes for operator equations that combine low-rank approximation in tensor formats and adaptive approximation in a basis. Under fairly general assumptions, we obtain a rigorous…

Numerical Analysis · Mathematics 2014-03-17 Markus Bachmayr , Wolfgang Dahmen

We investigate traversable wormhole solutions within the framework of $f(\mathscr{Q},\mathscr{L}_m)$ gravity, a symmetric teleparallel theory featuring non-minimal coupling between geometry and matter. Adopting a linear functional form…

General Relativity and Quantum Cosmology · Physics 2026-01-15 K. Suhasini , G. Ravi Kiran , N. S. Kavya , C. S. Varsha , V. Venkatesha

In this work, we consider wormhole geometries in third-order Lovelock gravity and investigate the possibility that these solutions satisfy the energy conditions. In this framework, by applying a specific equation of state, we obtain exact…

General Relativity and Quantum Cosmology · Physics 2016-06-09 Mohammad Reza Mehdizadeh , Francisco S. N. Lobo

Morris \& Thorne \cite{morris1} proposed geometrical objects called traversable wormholes that act as bridges in connecting two spacetimes or two different points of the same spacetime. The geometrical properties of these wormholes depend…

General Relativity and Quantum Cosmology · Physics 2019-07-17 Nisha Godani , Gauranga C. Samanta

We have proposed a novel shape function on which the metric that models traversable wormholes is dependent. Using this shape function, the energy conditions, equation of state and anisotropy parameter are analyzed in $f(R)$ gravity,…

General Relativity and Quantum Cosmology · Physics 2020-05-19 Gauranga C. Samanta , Nisha Godani , Kazuharu Bamba

Reduced order models are computationally inexpensive approximations that capture the important dynamical characteristics of large, high-fidelity computer models of physical systems. This paper applies machine learning techniques to improve…

Machine Learning · Computer Science 2015-11-11 Azam Moosavi , Razvan Stefanescu , Adrian Sandu

The advantages and difficulties of application of Pad\'e approximants to two-dimensional regression analysis are discussed. New formulation of residuals is suggested in the method of least squares. It leads to a system of linear equations…

Methodology · Statistics 2022-08-23 Glib Yevkin , Olexandr Yevkin

We present an analysis of the classic wormhole geometries based on conformal Weyl gravity, rather than standard general relativity. The main characteristics of the resulting traversable wormholes remain the same as in the seminal study by…

General Relativity and Quantum Cosmology · Physics 2016-05-26 Gabriele U. Varieschi , Kellie L. Ault