English
Related papers

Related papers: Primordial magnetic fields: consistent initial con…

200 papers

(Abridged) This paper introduces the formalism which connects between rotation measure ($\RM$) measurements for extragalactic sources and the cosmological magnetic field power spectrum. It is shown that the amplitude and shape of the…

Astrophysics · Physics 2016-08-30 Tsafrir Kolatt

We study the importance of baryonic physics on predictions of the matter power spectrum as it is relevant for forthcoming weak lensing surveys. We quantify the impact of baryonic physics using a set of three cosmological numerical…

Astrophysics · Physics 2009-11-13 Douglas H. Rudd , Andrew R. Zentner , Andrey V. Kravtsov

We present new limits on the amplitude of potential primordial magnetic fields (PMFs) using temperature and polarization measurements of the cosmic microwave background (CMB) from Planck, BICEP2/Keck Array, POLARBEAR, and SPTpol. We reduce…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Dylan R. Sutton , Chang Feng , Christian L. Reichardt

In this thesis, we aim to investigate the mechanisms underlying the genesis of magnetic fields in the Universe and explore their potential in addressing the matter-antimatter asymmetry. We construct consistent models that generate the…

General Relativity and Quantum Cosmology · Physics 2024-03-21 Ashu Kushwaha

Magnetic fields are observed in star forming regions. However simulations of the late stages of star formation that do not include magnetic fields provide a good fit to the properties of young stars including the initial mass function (IMF)…

Solar and Stellar Astrophysics · Physics 2018-10-17 C. J. Nixon , J. E. Pringle

If vector type perturbations are present in the primordial plasma before recombination, the generation of magnetic fields is known to be inevitable through the Harrison mechanism. In the context of the standard cosmological perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Shohei Saga , Kiyotomo Ichiki , Keitaro Takahashi , Naoshi Sugiyama

In two previous papers, we presented simulations of the first galaxies in a representative volume of the Universe. The simulations are unique because we model feedback-regulated galaxy formation, using time-dependent,…

Astrophysics · Physics 2008-11-26 Massimo Ricotti , Nickolay Y. Gnedin , J. Michael Shull

Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…

Astrophysics of Galaxies · Physics 2017-11-08 Michael Rieder , Romain Teyssier

We propose a novel method to probe primordial gravitational waves by means of primordial black holes (PBHs). When the amplitude of primordial tensor perturbations on comoving scales much smaller than those relevant to Cosmic Microwave…

General Relativity and Quantum Cosmology · Physics 2016-05-17 Tomohiro Nakama , Teruaki Suyama

We discuss the implications of causality on a primordial magnetic field. We show that the residual field on large scales is much more suppressed than usually assumed and that a helical component is even more reduced. Due to this strong…

Astrophysics · Physics 2009-11-07 Ruth Durrer , Chiara Caprini

The existence of primordial magnetic fields can induce matter perturbations with additional power at small scales as compared to the usual $\Lambda$CDM model. We study its implication within the context of two-point shear correlation…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Kanhaiya L. Pandey , Shiv K. Sethi

At metallicities lower than that of the Small Magellanic Cloud, it remains essentially unexplored how fossil magnetic fields, forming large-scale magnetospheres, could affect the evolution of massive stars, thereby impacting the fundamental…

Solar and Stellar Astrophysics · Physics 2024-07-31 Z. Keszthelyi , J. Puls , G. Chiaki , H. Nagakura , A. ud-Doula , T. Takiwaki , N. Tominaga

We investigate the influence of cosmic magnetic fields on gravitational wave perturbations, and find exact solutions on large scales. We show that a large-scale magnetic field can generate large-scale non-decaying gravitational waves. In…

Astrophysics · Physics 2009-11-06 Roy Maartens , Christos Tsagas , Carlo Ungarelli

Star-forming gas clouds are strongly magnetized, and their ionization fractions are high enough to place them close to the regime of ideal magnetohydrodyamics on all but the smallest size scales. In this review we discuss the effects of…

Astrophysics of Galaxies · Physics 2019-02-08 Mark R. Krumholz , Christoph Federrath

The possibility that a relevant fraction of the dark matter might be comprised of Primordial Black Holes (PBHs) has been seriously reconsidered after LIGO's detection of a $\sim 30 M_{\odot}$ binary black holes merger. Despite the strong…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-31 José Luis Bernal , Nicola Bellomo , Alvise Raccanelli , Licia Verde

Some recent observations of the cosmic microwave background (CMB) anisotropies and the large-scale structure of the Universe imply cosmic parity violation. Among possible parity-violating sources, helical primordial magnetic fields (PMFs)…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-12 Kaito Yura , Shohei Saga , Maresuke Shiraishi , Shuichiro Yokoyama

Faraday rotation induced B-modes can provide a distinctive signature of primordial magnetic fields because of their characteristic frequency dependence and because they are only weakly damped on small scales, allowing them to dominate…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-29 Levon Pogosian , Amit P. S. Yadav , Yi-Fung Ng , Tanmay Vachaspati

Primordial magnetic fields are often thought to be the early Universe seeds that have bloomed into what we observe today as galactic and extra-galactic magnetic fields. Owing to their minuscule strength, primordial magnetic fields are very…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-11 Sabir Ramazanov , Federico R. Urban , Alexander Vikman

Recent cosmological hydrodynamic simulations have suggested that the first stars in the universe often form as binary or multiple systems. However, previous studies typically overlooked the potential influence of magnetic fields during this…

Astrophysics of Galaxies · Physics 2024-05-27 Kenji Eric Sadanari , Kazuyuki Omukai , Kazuyuki Sugimura , Tomoaki Matsumoto , Kengo Tomida

We constrain a stochastic background of primordial magnetic field (PMF) by its contribution to the angular power spectrum of cosmic microwave background anisotropies. We parametrize such stochastic background by a power-law spectrum with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Daniela Paoletti , Fabio Finelli