Article
Physics, Particles & Fields
Niccolo Cribiori, Dieter Luest, Marco Scalisi
Summary: The study introduces a new swampland conjecture suggesting that the limit of vanishing gravitino mass corresponds to the massless limit of an infinite tower of states, leading to the breakdown of effective field theory. This proposal is tested in models from string theory compactification to four dimensions, with a general relation identified between gravitino mass and abelian gauge coupling. The researchers discuss the phenomenological implications of their conjecture in (quasi-)de Sitter backgrounds and derive a lower bound for the gravitino mass based on the Hubble parameter.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
D. Smith, D. Z. Besson, C. Deaconu, S. Prohira, P. Allison, L. Batten, J. J. Beatty, W. R. Binns, V Bugaev, P. Cao, C. Chen, P. Chen, J. M. Clem, A. Connolly, L. Cremonesi, P. Dasgupta, P. W. Gorham, M. H. Israel, T. C. Liu, A. Ludwig, S. Matsuno, C. Miki, J. Nam, A. Novikov, R. J. Nichol, E. Oberla, R. Prechelt, B. F. Rauch, J. Russell, D. Saltzberg, D. Seckel, G. S. Varner, A. G. Vieregg, S. A. Wissel
Summary: The ANITA experiment is designed to detect ultra-high energy neutrinos through radio emissions, but has also discovered anomalous events from ultra-high energy charged cosmic rays. The observed anomalies may require non-Standard Model physics for explanation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Sergei F. Shandarin
Summary: The study examines the density distribution of dark matter at caustic surfaces and the corresponding geometrical features, as well as the methods and challenges in identifying caustics in numerical simulations. The halo boundary is found to be asymmetrical, but a convex hull is a good approximation. Analyses of kinetic and potential energies, as well as examination of the two-dimensional phase space, confirm that the halo is gravitationally bound. The discovery of non-ellipsoidal oval shapes in a sample of halos from large simulations shows promise for further detailed analysis on higher resolution simulations.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Enrique Gaztanaga
Summary: The cosmological constant Λ is proposed to correspond to a boundary term in classical General Relativity, related to average density and pressure. This explains the relation of Λ to matter density and why other contributions do not produce cosmic expansion.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Biswajit Pandey
Summary: The proposed method uses Renyi entropy to test homogeneity in three-dimensional spatial distributions, effectively characterizing any inhomogeneities and identifying transition scales to homogeneity. It can be applied to study cosmic homogeneity in galaxy redshift surveys of current and future generations.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Xin Wang
Summary: The paper studies the statistical evolution of the large-scale structure, with a focus on the joint probability distribution function. The evolution equation of this PDF describing probability conservation and the characteristic curves as effective dynamics are explored. This statistical approach provides valuable insights into scale interactions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Andrea Giusti, Valerio Faraoni
Summary: The concept of turnaround surface in an accelerating universe has been generalized to accommodate arbitrarily large deviations from spherical symmetry, bridging the gap between ideal theoretical literature and real-world observations. An analytical application of this concept has been used to characterize small deviations from spherical symmetry, extending previous results to scalar-tensor gravity.
Article
Astronomy & Astrophysics
Eleonora Di Valentino, William Giare, Alessandro Melchiorri, Joseph Silk
Summary: In this study, the global agreement between observations of the cosmic microwave background (CMB) from the Atacama Cosmology Telescope and the Planck satellite is examined in different cosmological models with additional parameters. The Suspiciousness statistic is used to quantify the tension between the two experiments. Results show that the tension is reduced to 1.8 sigma when the effective number of relativistic particles is lower than the standard value, and ranges between 2.3 sigma and 3.5 sigma in other extended models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
R. U. Abbasi, M. Abe, T. Abu-Zayyad, M. Allen, Y. Arai, E. Barcikowski, J. W. Belz, D. R. Bergman, S. A. Blake, R. Cady, B. G. Cheon, J. Chiba, M. Chikawa, T. Fujii, K. Fujisue, K. Fujita, R. Fujiwara, M. Fukushima, R. Fukushima, G. Furlich, W. Hanlon, M. Hayashi, N. Hayashida, K. Hibino, R. Higuchi, K. Honda, D. Ikeda, T. Inadomi, N. Inoue, T. Ishii, H. Ito, D. Ivanov, H. Iwakura, H. M. Jeong, S. Jeong, C. C. H. Jui, K. Kadota, F. Kakimoto, O. Kalashev, K. Kasahara, S. Kasami, H. Kawai, S. Kawakami, S. Kawana, K. Kawata, E. Kido, H. B. Kim, J. H. Kim, M. H. Kim, S. W. Kim, Y. Kimura, S. Kishigami, V. Kuzmin, M. Kuznetsov, Y. J. Kwon, K. H. Lee, B. Lubsandorzhiev, J. P. Lundquist, K. Machida, H. Matsumiya, T. Matsuyama, J. N. Matthews, R. Mayta, M. Minamino, K. Mukai, I. Myers, S. Nagataki, K. Nakai, R. Nakamura, T. Nakamura, Y. Nakamura, T. Nonaka, H. Oda, S. Ogio, M. Ohnishi, H. Ohoka, Y. Oku, T. Okuda, Y. Omura, M. Ono, R. Onogi, A. Oshima, S. Ozawa, I. H. Park, M. S. Pshirkov, J. Remington, D. C. Rodriguez, G. I. Rubtsov, D. Ryu, H. Sagawa, R. Sahara, Y. Saito, N. Sakaki, T. Sako, N. Sakurai, K. Sano, K. Sato, T. Seki, K. Sekino, P. D. Shah, F. Shibata, N. Shibata, T. Shibata, H. Shimodaira, B. K. Shin, H. S. Shin, D. Shinto, J. D. Smith, P. Sokolsky, N. Sone, B. T. Stokes, T. A. Stroman, T. Suzawa, Y. Takagi, Y. Takahashi, M. Takamura, M. Takeda, R. Takeishi, A. Taketa, M. Takita, Y. Tameda, H. Tanaka, K. Tanaka, M. Tanaka, Y. Tanoue, S. B. Thomas, G. B. Thomson, P. Tinyakov, I. Tkachev, H. Tokuno, T. Tomida, S. Troitsky, R. Tsuda, Y. Tsunesada, Y. Uchihori, S. Udo, T. Uehama, F. Urban, T. Wong, K. Yada, M. Yamamoto, K. Yamazaki, J. Yang, K. Yashiro, F. Yoshida, Y. Zhezher, Z. Zundel
Summary: This paper reports results on the measurement of the cosmic-ray composition using the TALE air fluorescence detector, focusing on X-max distributions of showers observed over a wide energy range. The study shows that the composition of cosmic rays becomes heavier with increasing energy, consistent with a rigidity-dependent cutoff of events from Galactic sources. Additionally, a change in the cosmic-ray composition is observed at energies just above 10(17) eV.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Xiaohan Wu, Julian B. Munoz, Daniel J. Eisenstein
Summary: We propose a Lagrangian model for galaxy clustering bias, in which a neural network is trained using the local properties of the initial density field to predict the late-time mass-weighted halo field. We find that including three coarsely spaced smoothing scales gives the best recovery of the halo power spectrum, and adding more scales may cause underestimation and overfitting. We demonstrate that the fitted halo-to-mass ratio can be described by two principal components in the original high-dimensional feature space, and re-training the neural network with these components improves the matching of the halo power spectrum.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Felix Arjun Kuhn, Simon Birrer, Claudio Bruderer, Adam Amara, Alexandre Refregier
Summary: The combined cosmic shear analysis of strong lensing and galaxy shape measurements allows for a 2-sigma detection of the cross-correlation signal between the two complementary measurements. With large samples of lenses available in the future, the covariance of the signal of the two probes enables systematic checks and cross-calibration.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Luke Hart, Jens Chluba
Summary: Varying fundamental constants can be constrained by measurements of the cosmic microwave background. A model-independent principal component analysis is performed to obtain new constraints on these variations. No significant departures from the standard model are found. Future improvements are anticipated. However, further research is needed to understand the origin of the Hubble tension.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Joe Zhiyu Chen, Amol Upadhye, Yvonne Y. Y. Wong
Summary: This study investigates the clustering of cosmic neutrino population using a multi-fluid perturbation theory and finds that nonlinear treatment enhances small-scale neutrino power significantly. The findings are valuable for experiments probing the local neutrino density and velocity.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Luis A. Anchordoqui, Vernon Barger, Danny Marfatia, Mary Hall Reno, Thomas J. Weiler
Summary: IceCube has observed a flux of cosmic neutrinos, with a bump in the energy range 10 less than or similar to E/TeV less than or similar to 100, creating tension with gamma-ray data from the Fermi satellite. This tension is interpreted as evidence for hidden cosmic-ray accelerators. The study proposes an alternative explanation based on cold dark matter and sterile neutrinos.
Article
Astronomy & Astrophysics
Yilin Chen, Alexander Vilenkin
Summary: The process of pair production in a constant electric field is similar to bubble nucleation in a false vacuum. Each observer will still see nucleation to occur in its own rest frame, regardless of the motion of other observers. However, if the relative velocity of the two observers is high enough, particles and antiparticles of the pair can be observed moving towards each other with very large momenta, contrary to the usual expectation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Applied
H. Sugai, P. A. R. Ade, Y. Akiba, D. Alonso, K. Arnold, J. Aumont, J. Austermann, C. Baccigalupi, A. J. Banday, R. Banerji, R. B. Barreiro, S. Basak, J. Beall, S. Beckman, M. Bersanelli, J. Borrill, F. Boulanger, M. L. Brown, M. Bucher, A. Buzzelli, E. Calabrese, F. J. Casas, A. Challinor, V. Chan, Y. Chinone, J. -F. Cliche, F. Columbro, A. Cukierman, D. Curtis, P. Danto, P. de Bernardis, T. de Haan, M. De Petris, C. Dickinson, M. Dobbs, T. Dotani, L. Duband, A. Ducout, S. Duff, A. Duivenvoorden, J. -M. Duval, K. Ebisawa, T. Elleflot, H. Enokida, H. K. Eriksen, J. Errard, T. Essinger-Hileman, F. Finelli, R. Flauger, C. Franceschet, U. Fuskeland, K. Ganga, J. -R. Gao, R. Genova-Santos, T. Ghigna, A. Gomez, M. L. Gradziel, J. Grain, F. Grupp, A. Gruppuso, J. E. Gudmundsson, N. W. Halverson, P. Hargrave, T. Hasebe, M. Hasegawa, M. Hattori, M. Hazumi, S. Henrot-Versille, D. Herranz, C. Hill, G. Hilton, Y. Hirota, E. Hivon, R. Hlozek, D. -T. Hoang, J. Hubmayr, K. Ichiki, T. Iida, H. Imada, K. Ishimura, H. Ishino, G. C. Jaehnig, M. Jones, T. Kaga, S. Kashima, Y. Kataoka, N. Katayama, T. Kawasaki, R. Keskitalo, A. Kibayashi, T. Kikuchi, K. Kimura, T. Kisner, Y. Kobayashi, N. Kogiso, A. Kogut, K. Kohri, E. Komatsu, K. Komatsu, K. Konishi, N. Krachmalnicoff, C. L. Kuo, N. Kurinsky, A. Kushino, M. Kuwata-Gonokami, L. Lamagna, M. Lattanzi, A. T. Lee, E. Linder, B. Maffei, D. Maino, M. Maki, A. Mangilli, E. Martinez-Gonzalez, S. Masi, R. Mathon, T. Matsumura, A. Mennella, M. Migliaccio, Y. Minami, K. Mistuda, D. Molinari, L. Montier, G. Morgante, B. Mot, Y. Murata, J. A. Murphy, M. Nagai, R. Nagata, S. Nakamura, T. Namikawa, P. Natoli, S. Nerval, T. Nishibori, H. Nishino, Y. Nomura, F. Noviello, C. O'Sullivan, H. Ochi, H. Ogawa, H. Ogawa, H. Ohsaki, I. Ohta, N. Okada, N. Okada, L. Pagano, A. Paiella, D. Paoletti, G. Patanchon, F. Piacentini, G. Pisano, G. Polenta, D. Poletti, T. Prouve, G. Puglisi, D. Rambaud, C. Raum, S. Realini, M. Remazeilles, G. Roudil, J. A. Rubino-Martin, M. Russell, H. Sakurai, Y. Sakurai, M. Sandri, G. Savini, D. Scott, Y. Sekimoto, B. D. Sherwin, K. Shinozaki, M. Shiraishi, P. Shirron, G. Signorelli, G. Smecher, P. Spizzi, S. L. Stever, R. Stompor, S. Sugiyama, A. Suzuki, J. Suzuki, E. Switzer, R. Takaku, H. Takakura, S. Takakura, Y. Takeda, A. Taylor, E. Taylor, Y. Terao, K. L. Thompson, B. Thorne, M. Tomasi, H. Tomida, N. Trappe, M. Tristram, M. Tsuji, M. Tsujimoto, C. Tucker, J. Ullom, S. Uozumi, S. Utsunomiya, J. Van Lanen, G. Vermeulen, P. Vielva, F. Villa, M. Vissers, N. Vittorio, F. Voisin, I. Walker, N. Watanabe, I. Wehus, J. Weller, B. Westbrook, B. Winter, E. Wollack, R. Yamamoto, N. Y. Yamasaki, M. Yanagisawa, T. Yoshida, J. Yumoto, M. Zannoni, A. Zonca
JOURNAL OF LOW TEMPERATURE PHYSICS
(2020)
Article
Physics, Multidisciplinary
Jeff A. Dror, Takashi Hiramatsu, Kazunori Kohri, Hitoshi Murayama, Graham White
PHYSICAL REVIEW LETTERS
(2020)
Article
Astronomy & Astrophysics
Masahiro Kawasaki, Kazunori Kohri, Takeo Moroi, Kai Murai, Hitoshi Murayama
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2020)
Article
Astronomy & Astrophysics
Kazunori Kohri, Takahiro Terada
Summary: The NANOGrav collaboration recently announced evidence of an isotropic stochastic process, potentially the first detection of the stochastic gravitational-wave background. They discuss the possibility that this signal is caused by second-order gravitational waves associated with the formation of solar-mass primordial black holes, and propose testing methods for future observations.
Article
Astronomy & Astrophysics
J. Chluba, M. H. Abitbol, N. Aghanim, Y. Ali-Haimoud, M. Alvarez, K. Basu, B. Bolliet, C. Burigana, P. de Bernardis, J. Delabrouille, E. Dimastrogiovanni, F. Finelli, D. Fixsen, L. Hart, C. Hernandez-Monteagudo, J. C. Hill, A. Kogut, K. Kohri, J. Lesgourgues, B. Maffei, J. Mather, S. Mukherjee, S. P. Patil, A. Ravenni, M. Remazeilles, A. Rotti, J. A. Rubino-Martin, J. Silk, R. A. Sunyaev, E. R. Switzer
Summary: This paper discusses the unique scientific opportunities presented by studying spectral distortions of the cosmic microwave background, emphasizing the importance of precision spectroscopy using existing technology. It highlights the potential for new discoveries in physics and challenges to our current understanding of the laws of nature, offering valuable insights into the early Universe.
EXPERIMENTAL ASTRONOMY
(2021)
Article
Astronomy & Astrophysics
Katsuaki Asano, Yoichi Asaoka, Yosui Akaike, Norita Kawanaka, Kazunori Kohri, Holger M. Motz, Toshio Terasawa
Summary: The study shows that even with simple power-law diffusion coefficients, similar spectra to the CALET spectrum can be produced. In the energy range of 2-4 TeV, one to three nearby supernovae can contribute to a significant portion of the CALET flux, while ten or more unknown and distant supernovae account for the remaining portion of the flux. The CALET spectrum exhibits a sharp drop at around 1 TeV, suggesting a contribution from an extraordinary event occurred approximately 400 thousand years ago.
ASTROPHYSICAL JOURNAL
(2022)
Review
Physics, Multidisciplinary
Bernard Carr, Kazunori Kohri, Yuuiti Sendouda, Jun'ichi Yokoyama
Summary: In this article, constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over a range of masses are updated. The discussion covers the reasons why PBHs smaller than a certain mass threshold are constrained and the various constraints on PBHs larger than that threshold.
REPORTS ON PROGRESS IN PHYSICS
(2021)
Article
Physics, Multidisciplinary
Kazunori Kohri, Kei-ichi Maeda
Summary: We discuss cosmology based on the cuscuton gravity theory to resolve the anomaly of the observational He-4 abundance. A smaller gravitational constant G(cos) compared to Newton's constant G(N) is required, and a negative squared mass of a non-dynamical scalar field is obtained to fit the data. This suggests the need for modified gravity theories.
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2022)
Article
Astronomy & Astrophysics
Kazunori Kohri, Toyokazu Sekiguchi, Sai Wang
Summary: In this paper, the scenarios of super-Eddington accretion onto black holes at high redshifts are studied, which are expected to be seeds for evolving into supermassive black holes. By comparing observational data with theoretical predictions, an upper bound on the initial mass of the seed black holes is obtained, and some implications for primordial black holes as seed black holes are discussed.
Article
Astronomy & Astrophysics
Takahisa Igata, Kazunori Kohri, Kota Ogasawara
Summary: The study focuses on the situation where a light source in the vicinity of the innermost stable circular orbit (ISCO) of a Kerr black hole experiences a gentle perturbation, leading to photon escape probabilities and energy blueshifts. It is found that the last radius at which more than 50% of emitted photons can escape to infinity lies approximately halfway between the ISCO radius and the event horizon radius.
Proceedings Paper
Astronomy & Astrophysics
Y. Asaoka, O. Adriani, Y. Akaike, K. Asano, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, A. Bruno, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kohri, H. S. Krawczynski, J. F. Krizmanic, J. Link, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, A. A. Moiseev, M. Mori, N. Mori, H. M. Motz, K. Munakata, S. Nakahira, J. Nishimura, G. A. de Nolfo, S. Okuno, N. Opsina, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, V. Pal'shin, P. Papini, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, S. Sugita, J. E. Suh, A. Sulaj, I. Takahashi, M. Takita, T. Tamura, T. Terasawa, S. Torii, Y. Tsunesada, Y. Uchihori, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida
16TH INTERNATIONAL CONFERENCE ON TOPICS IN ASTROPARTICLE AND UNDERGROUND PHYSICS (TAUP 2019)
(2020)
Proceedings Paper
Astronomy & Astrophysics
Keisuke Inomata, Kazunori Kohri, Tomohiro Nakama, Takahiro Terada
16TH INTERNATIONAL CONFERENCE ON TOPICS IN ASTROPARTICLE AND UNDERGROUND PHYSICS (TAUP 2019)
(2020)
Proceedings Paper
Astronomy & Astrophysics
Keisuke Inomata, Kazunori Kohri, Tomohiro Nakama, Takahiro Terada
16TH INTERNATIONAL CONFERENCE ON TOPICS IN ASTROPARTICLE AND UNDERGROUND PHYSICS (TAUP 2019)
(2020)
Correction
Astronomy & Astrophysics
Sai Wang, Takahiro Terada, Kazunori Kohri
Article
Astronomy & Astrophysics
Keisuke Inomata, Kazunori Kohri, Tomohiro Nakama, Takahiro Terada
