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Matter in the Universe is arranged in a cosmic web, with a filament of matter typically connecting each neighbouring galaxy pair, separated by tens of millions of light-years. A quadrupolar pattern of the spin field around filaments is known to influence the spins of galaxies and haloes near them, but it remains unknown whether filaments themselves spin. Here, we measure dark-matter velocities around filaments in cosmological simulations, finding that matter generally rotates around them, much faster than around a randomly located axis. It also exhibits some coherence along the filament. The net rotational component is comparable to, and often dominant over, the known quadrupolar flow. The evidence of net rotations revises previous emphasis on a quadrupolar spin field around filaments. The full picture of rotation in the cosmic web is more complicated and multiscale than a network of spinning filamentary rods, but we argue that filament rotation is substantial enough to be an essential part of the picture. It is likely that the longest coherently rotating objects in the Universe are filaments. Also, we speculate that this rotation could provide a mechanism to generate or amplify intergalactic magnetic fields in filaments.
Soon after the first QSO was identified, Gunn & Peterson searched for the expected characteristic absorption trough on the blueward side of Lya in the spectrum of the QSO due to an Intergalactic Medium (IGM). They failed to find it, placing a constra
We investigate the spin evolution of dark matter haloes and their dependence on the number of connected filaments from the cosmic web at high redshift (spin-filament relation hereafter). To this purpose, we have simulated $5000$ haloes in the mass ra
When galaxy clusters collide, they generate shock fronts in the hot intracluster medium. Observations of these shocks can provide valuable information on the merger dynamics and physical conditions in the cluster plasma, and even help constrain the n
Intergalactic scintillation of distant quasars is sensitive to free electrons and therefore complements Ly$alpha$ absorption line experiments probing the neutral intergalactic medium (IGM). We present a new scheme to compute IGM refractive scintillat
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