Article
Astronomy & Astrophysics
Kimmo Kainulainen, Sami Nurmi, Enrico D. Schiappacasse, Tsutomu T. Yanagida
Summary: The study investigates the potential of primordial black holes as sources of fast radio bursts, suggesting that PBHs may release energy through magnetic reconnection during collisions with neutron stars. It also proposes that PBHs could lose energy and be captured by neutron stars during encounters. The results indicate that the parameter space of PBHs as all dark matter is accidentally consistent with the rate of producing fast radio bursts observed.
Article
Computer Science, Information Systems
Zhong Xi, Xuan Liu, Juan Luo, Shigeng Zhang, Song Guo
Summary: This article presents effective solutions to the problem of estimating the number of dynamic tags in RFID systems, taking into account missing and unknown tags. By utilizing the time slot reuse method and SSR protocol, accuracy and time efficiency of estimation can be greatly improved. However, the performance of SSR degrades significantly when there is a notable disparity between the numbers of different tag types, leading to the proposal of an enhanced version, ESSR.
IEEE INTERNET OF THINGS JOURNAL
(2021)
Article
Astronomy & Astrophysics
Matteo Biagetti, Alex Cole, Gary Shiu
Summary: The study presents an analysis pipeline utilizing persistent homology to characterize the topology of large scale structure and extract cosmological constraints. By examining the impact of primordial local non-Gaussianity on dark matter halo distribution through N-body simulations, they detected non-zero f(NL)(loc) on multiple cubic volumes. The method effectively addresses degeneracies between different topological signatures and provides interpretable statistics for both reproducing previous results and making new predictions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Hiroki Nagakura, Masamichi Zaizen
Summary: We conducted systematic numerical simulations in spherical symmetry to study fast neutrino-flavor conversion (FFC) with both small-scale and large-scale simulations. Our findings indicate that FFCs can reach a quasisteady state, and the nonlinear phase is determined by the angular structures of the electron neutrino lepton number (ELN) and the heavy neutrino lepton number. We propose a new approximate scheme of FFC based on our simulations, which can be easily incorporated into existing classical neutrino transport codes for studying core-collapse supernova and binary neutron star merger.
Article
Astronomy & Astrophysics
S. Libanore, M. C. Artale, D. Karagiannis, M. Liguori, N. Bartolo, Y. Bouffanais, N. Giacobbo, M. Mapelli, S. Matarrese
Summary: Clustering measurements of Gravitational Wave (GW) mergers in Luminosity Distance Space can be used as a powerful tool for Cosmology in the future. By considering tomographic measurements of the Angular Power Spectrum of mergers in different detector networks, Fisher forecasts for cosmological and merger bias parameters can be produced, showing significant improvements in more advanced scenarios. Regardless of the specific constraining power of different experiments, this type of analysis presents interesting insights into the physical nature and properties of GW mergers.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Heling Deng
Summary: The Peters formula used to estimate the merger time of black hole systems may underestimate the event rate in certain scenarios, leading to a potential peak in the energy density spectrum of the gravitational wave background; the merging time of black holes could vary and affect the suppression of the gravitational wave background spectrum at high frequencies.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Marika Asgari, Indiarose Friswell, Mijin Yoon, Catherine Heymans, Andrej Dvornik, Benjamin Joachimi, Patrick Simon, Joe Zuntz
Summary: The study introduces a mitigation strategy to reduce the impact of non-linear galaxy bias on the joint cosmological analysis of weak lensing and galaxy surveys, utilizing Psi-statistic to minimize contributions from smallest physical scales and showing comparable constraining power to standard two-point galaxy clustering statistics. It demonstrates a significant decrease in bias on cosmological parameter S-8 when analyzing Psi-statistics compared to standard two-point correlation functions, highlighting the importance of moving towards new statistics less sensitive to smallest physical scales in 3 x 2pt analyses.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Nicolas Chartier, Benjamin D. Wandelt
Summary: The study proposes a new method to address the challenge of estimating the covariance matrix Sigma with a large number of simulations. By combining a small number of simulations with fast surrogates, the method obtains low-noise estimates of Sigma that are unbiased by construction. The numerical examples show significant variance reductions for different elements of the matter power spectrum covariance matrix using this method.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Multidisciplinary
Keisuke Inomata, Masahiro Kawasaki, Kyohei Mukaida, Tsutomu T. Yanagida
Summary: The study suggests that the axionlike curvaton model can explain the primordial black holes in both the LIGO-Virgo events and NANOGrav results, with the non-Gaussianity suppressing the gravitational waves associated with PBHs.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Vicente Atal, Albert Sanglas, Nikolaos Triantafyllou
Summary: The study suggests that the signal detected by NANOGrav could be from the stochastic gravitational wave background of binary mergers of primordial Stupendously Large Black Holes, which contribute roughly 0.1% of the dark matter. Overcoming the stringent limits from mu distortions of the CMB is possible if the perturbations in these black holes derive from the expected non-Gaussian distribution of fluctuations. However, the stochastic background from binaries with masses less than or equal to 10^11M-solar masses is excluded by constraints from large scale structure.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
G. A. Pena, G. N. Candlish
Summary: The late-time effect of primordial non-Gaussianity in the early Universe is studied in this work. By generating multiple realizations of cosmological structure and analyzing the matter power spectrum, bispectrum, and trispectrum, it is found that the initial non-Gaussianity has only a small imprint on the first three polyspectra. Some models show interesting scale-dependent deviations from the Gaussian case in the bispectrum and trispectrum, although the signal is at most at the per cent level.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. Bhagwat, V De Luca, G. Franciolini, P. Pani, A. Riotto
Summary: This study investigates the significant impact of using physically motivated prior distributions on inferring black hole parameters from gravitational-wave data. In particular, when analyzing primordial black holes, incorporating priors can change the inferred mass ratio and spin significantly.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Giacomo Ferrante, Gabriele Franciolini, Antonio Junior Iovino, Alfredo Urbano
Summary: We present a comprehensive formalism for computing the abundance of primordial black holes (PBHs) with local non-Gaussianity (NG) in the curvature perturbation field. We go beyond the traditional quadratic and cubic approximations and consider a generic functional form for NG. Our approach considers both narrow and broad power spectra. We show that the conventional perturbative approach is only reliable for narrow spectra, while for broad spectra, nonperturbative computations are necessary to obtain accurate results.
Article
Astronomy & Astrophysics
H. V. Ragavendra, Debika Chowdhury, L. Sriramkumar
Summary: A sharp cutoff in the primordial scalar power spectrum has been found to fit the cosmic microwave background data better compared to the standard power spectra that result from slow roll inflation. This study explores different inflation models with kinetically dominated initial conditions, as well as competing scenarios that also suppress scalar power on large scales. By comparing the models against Planck CMB data, it is found that the model where the background field remains on the inflationary attractor allows for analytical calculations and shows advantages in terms of scalar power and bispectra. Additionally, the behavior of the scalar bispectra can potentially help differentiate between the models.
Article
Astronomy & Astrophysics
Salome Mtchedlidze, Paola Dominguez-Fernandez, Xiaolong Du, Axel Brandenburg, Tina Kahniashvili, Shane O'Sullivan, Wolfram Schmidt, Marcus Brueggen
Summary: This article investigates the formation and evolution of primordial magnetic fields (PMFs) through cosmological simulations. The study finds that the observed magnetic field configuration retains information about the initial conditions, offering indirect evidence for understanding the early universe. Differences between competing models are revealed at different scales, and the spectral evolution of seed fields leaves imprints on the correlation length today. The article also discusses how forthcoming surveys can be used to probe the differences in rotation measures from highly ionized regions.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Donough Regan, Mark Hindmarsh
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2015)
Article
Astronomy & Astrophysics
Donough Regan, Mark Hindmarsh
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2015)
Article
Astronomy & Astrophysics
Donough Regan, Gemma J. Anderson, Matthew Hull, David Seery
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2015)
Article
Astronomy & Astrophysics
Donough Regan, Mateja Gosenca, David Seery
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2015)
Article
Astronomy & Astrophysics
Donough Regan, Dipak Munshi
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2015)
Article
Astronomy & Astrophysics
Chang Feng, Asantha Cooray, Joseph Smidt, Jon O'Bryan, Brian Keating, Donough Regan
Article
Astronomy & Astrophysics
Christian T. Byrnes, Donough Regan, David Seery, Ewan R. M. Tarrant
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2016)
Article
Astronomy & Astrophysics
Sam Young, Donough Regan, Christian T. Byrnes
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2016)
Article
Astronomy & Astrophysics
Lucia Fonseca de la Bella, Donough Regan, David Seery, Shaun Hotchkiss
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2017)
Article
Astronomy & Astrophysics
Dipak Munshi, Donough Regan
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2017)
Article
Astronomy & Astrophysics
Joyce Byun, Alexander Eggemeier, Donough Regan, David Seery, Robert E. Smith
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2017)
Article
Astronomy & Astrophysics
Gemma J. Anderson, Donough Regan, David Seery
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2014)
Article
Astronomy & Astrophysics
Donough Regan, Pia Mukherjee, David Seery
Article
Astronomy & Astrophysics
Christian T. Byrnes, Donough Regan, David Seery, Ewan R. M. Tarrant