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Related papers: Magnification bias as a novel probe for primordial…

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The existence of galaxy intrinsic clustering severely hampers the weak lensing reconstruction from cosmic magnification. In paper I \citep{Yang2011}, we proposed a minimal variance estimator to overcome this problem. By utilizing the…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Xinjuan Yang , Pengjie Zhang , Jun Zhang , Yu Yu

The magnetic fields we observe in galaxies today may have their origins in the very early universe. While a number of mechanisms have been proposed which lead to an appreciable field amplitude at early times, the subsequent evolution of the…

Astrophysics · Physics 2007-05-23 Sean M. Carroll , George B. Field

In the last decade the detection of individual massive dark matter sub-halos has been possible using potential correction formalism in strong gravitational lens imaging. Here we propose a statistical formalism to relate strong gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 Saikat Chatterjee , Léon V. E. Koopmans

There are at present more then 30 theories about the origin of cosmic magnetic fields at galactic and intergalactic scales. Most of them rely on concepts of elementary particle physics, like phase transitions in the early Universe, string…

Astrophysics · Physics 2007-05-23 E. Battaner , H. Lesch

We discuss the amplification of magnetic fields by the small-scale dynamo, a process that could efficiently produce strong magnetic fields in the first galaxies. In addition, we derive constraints on the primordial field strength from the…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-14 Dominik R. G. Schleicher , Jennifer Schober , Christoph Federrath , Francesco Miniati , Robi Banerjee , Ralf S. Klessen

The origin of large scale magnetic fields in the Universe is widely thought to be from early Universe processes, like inflation or phase transitions. These magnetic fields evolve via magnetohydrodynamic processes until the epoch of…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-04 Molly Abramson , Emma Clarke , Tina Kahniashvili , Sayan Mandal , Salome Mtchedlidze , Jennifer Schober

Magnetic fields are observed on nearly all scales in the universe, from stars and galaxies upto galaxy clusters and even beyond. The origin of cosmic magnetic fields is still an open question, however a large class of models puts its origin…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-19 Kerstin E. Kunze

Gravitational lensing magnification alters the observed spatial distribution of galaxies and must be accounted for to prevent biases in cosmological probes of the large-scale structure. We investigate its effects on the Dark Energy Survey…

Magnetic fields constitute an energetic component of the interstellar medium in galaxies and hence can affect the formation of galactic structures. Sensitive resolved radio continuum observations together with statistical studies in galaxy…

Astrophysics of Galaxies · Physics 2018-11-20 Fatemeh S. Tabatabaei

Gravitational lensing magnification modifies the observed spatial distribution of galaxies and can severely bias cosmological probes of large-scale structure if not accurately modelled. Standard approaches to modelling this magnification…

A possible explanation for the origin of the magnetic fields observed today in matter structures is that they were generated in the primordial universe. After briefly revising the model of a primordial stochastic magnetic field and…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Chiara Caprini

We study the lensing magnification effect on background galaxies. Differential magnification due to different magnifications of different source regions of a galaxy will change the lensed composite spectra. The derived properties of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Xinzhong Er , Junqiang Ge , Shude Mao

The explanation of the observed galactic magnetic fields may require the existence of a primordial magnetic field. Such a field may arise during the early cosmological phase transitions, or because of other particle physics related…

Astrophysics · Physics 2009-10-30 Kari Enqvist

We analyse several implications of lensing by the regular component of the galactic magnetic field upon the observed properties of ultra high energy cosmic rays. Magnetic fields deflect cosmic ray trajectories, causing flux…

Astrophysics · Physics 2009-10-31 Diego Harari , Silvia Mollerach , Esteban Roulet

Primordial magnetic fields (PMFs) are one of the plausible candidates for the origin of the observed large-scale magnetic fields. While many proposals have been made for the generation mechanism of PMFs by earlier studies, it remains a…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-12 Shohei Saga , Maresuke Shiraishi , Kazuyuki Akitsu , Teppei Okumura

Detailed physical processes of magnetic field generation from density fluctuations in the pre-recombination era are studied. Solving Maxwell equations and the generalized Ohm's law, the evolutions of the net charge density, the electric…

Astrophysics · Physics 2008-11-26 Keitaro Takahashi , Kiyotomo Ichiki , Naoshi Sugiyama

We study primordial magnetic field effects on the matter perturbations in the Universe. We assume magnetic field generation prior to the big bang nucleosynthesis (BBN), i.e. during the radiation dominated epoch of the Universe expansion,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Tina Kahniashvili , Yurii Maravin , Aravind Natarajan , Nicholas Battaglia , Alexander G. Tevzadze

The magnification of distant sources by mass clumps at lower ($z \leq 1$) redshifts is calculated analytically. The clumps are initially assumed to be galaxy group isothermal spheres with properties inferred from an extensive survey. The…

Astrophysics · Physics 2007-05-23 Richard Lieu , Jonathan P. D. Mittaz

Lensing in the context of rich clusters is normally quantified from small image distortions, yielding a relative mass distribution in the limit of weak lensing. Here we show the magnification effect of lensing can also be mapped over a…

Astrophysics · Physics 2016-08-30 Tom Broadhurst

The large-scale structure of the Universe has been observed to be characterized by long filaments, forming polyhedra, with a remarkable 100-200 Mpc periodicity, suggesting a regular network. The introduction of magnetic fields into the…

Astrophysics · Physics 2007-05-23 E. Battaner , E. Florido