Article
Physics, Particles & Fields
Polina Petriakova, Arkady A. Popov, Sergey G. Rubin
Summary: This paper discusses the origin of small parameters and aims to explain the Hierarchy problem. Flexible extra dimensions play a crucial role in the formation of physical parameters. The evolution of multidimensional metric starts from the Planck scale and ends with a static extra-dimensional metric and a 4-dimensional de Sitter space at high energies, leading to exponentially produced causally disconnected universes. Quantum fluctuations independently distort the metric within these universes, causing inflationary processes. Some universes asymptotically tend towards states characterized by small Hubble parameters. The explanation for the effective parameter reduction in the Higgs sector of the Standard Model lies in the presence of small-amplitude distributions of a scalar field in a fraction of these universes.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Particles & Fields
Ujjal Kumar Dey, Utpal Sarkar
Summary: A new scenario is proposed in this study to explain the dark energy problem through the formation of neutrino condensates. By breaking lepton number symmetry on a distant brane, the smallness of neutrino masses and the scale of dark energy are protected, with all lepton number violating effects suppressed in the extra dimensions. Additionally, a lepton number violating soft-term induced from the distant brane results in a light pseudo-Nambu-Goldstone boson acting as the mediator of the attractive force forming the condensates.
Article
Astronomy & Astrophysics
R. Jalalzadeh, S. Jalalzadeh, B. Malekolkalami
Summary: We investigate an isometrically embedded Bianchi type-V cosmology braneworld model in a D-dimensional bulk space. The model provides a fluid of geometric dark energy (GDE) and unification of fundamental forces similar to the Kaluza-Klein (KK) theory. Factors such as the Planck energy density, the fine structure constant, the muon mass, and the number of extra dimensions determine the density of the induced GDE. Our model predicts that the graviton has mass determined by the induced cosmological constant (CC). Our results suggest that if the Universe has 22 non-compact extra dimensions, they are compatible with observations of the standard model of cosmology. This model offers an alternative method for probing extra dimensions.
PHYSICS OF THE DARK UNIVERSE
(2023)
Article
Physics, Multidisciplinary
Pawel Pieranski, Mehdi Zeghal, Maria Helena Godinho, Patrick Judeinstein, Remi Bouffet-Klein, Bastien Liagre, Nicodeme Rouger
Summary: The concept of topological defects is universally applicable in condensed matter, including helical topological defects, dislocations, and vortices. This study focuses on the generation and behavior of primary tangles in cholesterics. The primary tangles can form double helices individually or combine according to simple algebraic rules.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Raja Chouket, Agnes Pellissier-Tanon, Alienor Lahlou, Ruikang Zhang, Diana Kim, Marie-Aude Plamont, Mingshu Zhang, Xi Zhang, Pingyong Xu, Nicolas Desprat, Dominique Bourgeois, Agathe Espagne, Annie Lemarchand, Thomas Le Saux, Ludovic Jullien
Summary: By illuminating reversibly photoswitchable fluorophores with different intensities, extra kinetic dimensions are introduced to overcome the limitation of label discrimination in fluorescence imaging. This strategy allows for the identification and discrimination of spectrally similar fluorescent proteins in a shorter time frame, opening promising perspectives for expanding the multiplexing capabilities of fluorescence imaging.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Particles & Fields
Nicolas Bernal, Andrea Donini, Miguel G. Folgado, Nuria Rius
Summary: This study explores the possibility of Dark Matter being made of Feebly Interacting Massive Particles interacting gravitationally with Standard Model particles in the Clockwork/Linear Dilaton (CW/LD) model. The study concludes that a significant region of parameter space in the CW/LD model can reproduce the observed Dark Matter relic abundance with scalar DM mass in the MeV range, similar to the results in the Randall-Sundrum (RS) scenario.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Abdul Jawad, Sadaf Maqsood, Shamaila Rani
Summary: The study investigates the influence of time dependent vacuum energy on the cosmic history and finds that the system has stable critical points in most cases, exhibiting attractive behavior of the universe.
PHYSICS OF THE DARK UNIVERSE
(2021)
Article
Mathematics
R. Oset Sinha, M. A. S. Ruas, R. Wik Atique
Summary: The paper discusses extra-nice dimensions and proves the density of locally stable families under certain conditions, similar to the denseness of stable maps. It also explores the relationship between extra-nice dimensions, discriminants of germs, and simplicity of germs.
MATHEMATISCHE ANNALEN
(2022)
Article
Astronomy & Astrophysics
M. Khlopunov, D. V. Gal'tsov
Summary: In the DGP model, the instability of the graviton leads to a modification of gravity at cosmological distances, resulting in the leakage of gravitational waves into an extra dimension. The calculation of the leakage intensity is challenging due to the violation of the Huygens principle in the five-dimensional bulk of the model. In this paper, a simplified problem of scalar radiation from a point charge localized on a brane in the framework of the scalar field analog of the DGP model is considered. The radiated part of the field is extracted using a generalized approach, and the dependence of the leakage intensity on the sphere radius is obtained. The results suggest that the leakage intensity is higher for low frequency signals. The possibility of detecting this leakage using gravitational-wave observatories is also analyzed.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Physics, Multidisciplinary
Ylann Rouzaire, Demian Levis
Summary: We investigate the ordering dynamics of a two-dimensional noisy Kuramoto model with short-range coupling and a Gaussian distribution of intrinsic frequencies. We find that the long-term properties of this system do not depend on the inertia of individual oscillators. The model does not exhibit any phase transition and the quench dynamics proceeds via domain growth. Topological defects are free and vortices perform a random walk similar to a self-avoiding random walk, exhibiting long-time super-diffusion with an anomalous exponent alpha = 3/2.
FRONTIERS IN PHYSICS
(2022)
Review
Multidisciplinary Sciences
Simon Yves, Xiang Ni, Andrea Alu
Summary: Topology is a branch of mathematics that studies the characteristics of objects that remain unchanged under continuous deformations. Recently, the powerful tools of topology have been used to study the electronic band structure of crystals, explaining topological phase transitions and the stability of certain band structures against perturbations. These findings have also led to the discovery of topological insulators, which have protected boundary states with unique transport properties. Furthermore, these discoveries have implications for sound control and manipulation technologies.
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
(2022)
Article
Astronomy & Astrophysics
D. V. Forero, C. Giunti, C. A. Ternes, O. Tyagi
Summary: The existence of large extra dimensions can be probed in various neutrino experiments. This study shows that the gallium anomaly can be explained by neutrino oscillations induced by the large extra dimension, but the preferred parameter space is in tension with other experimental data.
Article
Astronomy & Astrophysics
Christian Ferko, Gautam Satishchandran, Savdeep Sethi
Summary: A general formalism has been developed for treating radiative degrees of freedom near I thorn in theories with an arbitrary Ricci-flat internal space. The radiative modes are encoded in a generalized news tensor which decomposes into components of gravitational, electromagnetic, and scalar. The preferred gauge simplifies the asymptotic analysis of the full nonlinear Einstein equations and extends the Bondi-Metzner-Sachs (BMS) group to include angle-dependent isometries of the internal space.
Review
Optics
Eran Lustig, Mordechai Segev
Summary: Topological photonics is a rapidly growing field that has expanded its scope by incorporating non-spatial degrees of freedom. This offers the possibility to observe fundamental and exotic phenomena, with the next challenge being identified as enhancing the fundamental features of photonic topological systems.
ADVANCES IN OPTICS AND PHOTONICS
(2021)
Article
Astronomy & Astrophysics
Yuchen Du, Shammi Tahura, Diana Vaman, Kent Yagi
Summary: The study on the effect of compact extra dimensions on gravitational wave luminosity and waveform shows significant discrepancies when compared to gravitational wave and binary pulsar observations. The findings effectively rule out the possibility of such a simple compactified higher dimensions scenario. Additional compactified extra dimensions only exacerbate the discrepancy with 4D general relativity.
Article
Astronomy & Astrophysics
Antonio De Felice, Andreas Doll, Francois Larrouturou, Shinji Mukohyama
Summary: This study investigates spherically symmetric vacuum solutions in the context of the recently proposed type-II minimally modified gravity theory. Despite local differences from the traditional metric, the solutions can be recovered to the standard metric by imposing suitable asymptotic conditions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Antonio De Felice, Shinji Mukohyama, Masroor C. Pookkillath
Summary: The study proposes a theory of minimally modified gravity called VCDM to reduce the H-0 tension puzzle, and after analyzing data, a transition in the expansion history of the universe is found at low-redshift z around 0.3. By using low redshift Pantheon data, the local Hubble expansion rate today within this theory is inferred to be 73.69, leading to a reduced tension within the VCDM theory.
Article
Astronomy & Astrophysics
Robert Hagala, Antonio De Felice, David F. Mota, Shinji Mukohyama
Summary: Research indicates that the minimal theory of massive gravity shows small deviations from general relativity in halo density profiles and matter power spectra. However, there is a clear difference between MTMG and GR in terms of void density. While measuring void profiles is complex from an observational perspective, studying the abundance of dark matter halos is a better way to probe MTMG.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Antonio De Felice, Francois Larrouturou, Shinji Mukohyama, Michele Oliosi
Summary: MTBG is a stable and complete theory of alternative gravity, with cosmological solutions supporting two different branches, differing from GR in the scalar sector but retaining HRBG features in the tensor sector.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Antonio De Felice, Shinji Mukohyama
Summary: This paper introduces a new cosmological framework integrating dark matter into a minimally modified gravity model, maintaining the same number of gravitational degrees of freedom through a series of transformations. The framework includes two time-dependent free functions to achieve desired evolutions of Hubble expansion rate and effective gravitational constant for dark matter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Multidisciplinary
Antonio De Felice, Shinji Mukohyama, Kazufumi Takahashi
Summary: In modified gravity theories, the strong coupling problem of stealth solutions can be avoided with the use of U-DHOST theories. Additionally, the existence of a nonpropagating mode in U-DHOST theories is clarified.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Joshua A. Kable, Giampaolo Benevento, Noemi Frusciante, Antonio De Felice, Shinji Tsujikawa
Summary: This study investigates the physics of late-time cosmic acceleration using the cross-correlation power spectrum of the integrated Sachs-Wolfe effect and galaxy fluctuations in the cosmic microwave background temperature anisotropy. Three dark energy models belonging to a subclass of Horndeski theories are considered: Galileon Ghost Condensate (GGC), Generalized Cubic Covariant Galileon (GCCG), and K-mouflage. The GGC and GCCG models predict negative ISW-galaxy cross-correlations, while the K-mouflage model predicts a positive correlation similar to the A-cold-dark-matter (ACDM) model. By fitting the best-fit models to the ISW-galaxy cross-correlation power spectrum extracted from photometric redshift surveys, it is found that the GGC and GCCG models have a poorer fit compared to the ACDM model, attributed to the suppressed ISW tails caused by the cubic-order scalar self-interaction.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Antonio De Felice, Kei-ichi Maeda, Shinji Mukohyamaa, Masroor C. Pookkillatha
Summary: We study the collapse of a spherically symmetric dust cloud in the VCDM gravitational theory and find that it corresponds to a specific foliation of the Oppenheimer-Snyder solution in general relativity. The resulting collapse leads to a static configuration with a vanishing lapse function at a radius inside the apparent horizon. This implies the need for a UV completion to describe the physics inside the resulting black hole.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Antonio De Felice, Shinji Mukohyama, Kazufumi Takahashi
Summary: We investigate a generic quadratic higher-order scalar-tensor theory with a scor-datura term and show that exact stealth solutions cannot be realized in theories beyond DHOST. However, approximate stealth solutions exist, where the deviation from the exact stealth configuration is controlled by the mass scale M. The accretion of the scalar field leads to time-dependent approximately stealth solutions, which can be considered stealth at astrophysical scales for all practical purposes.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Antonio De Felice, Shinji Tsujikawa
Summary: Einsteinian cubic gravity is a higher-order gravitational theory that allows the existence of a static and spherically symmetric black hole solution with a modified Schwarzschild geometry induced by cubic curvature terms. However, this theory is plagued by ghost and Laplacian instabilities, with at least one of the dynamical perturbations behaving as a ghost mode. Additionally, one dynamical degree of freedom shows a negative sound speed squared -1/2 for high angular momentum modes.
Article
Astronomy & Astrophysics
Masato Minamitsuji, Antonio De Felice, Shinji Mukohyama, Michele Oliosi
Summary: We investigate the dynamical properties of static and spherically symmetric systems in the self-accelerating branch of the minimal theory of bigravity (MTBG). In the first part, we study the gravitational collapse of pressureless dust and find special solutions that represent gravitational collapse in MTBG. In the latter part, we study odd-parity perturbations of the Schwarzschild-de Sitter solutions and find that for higher-multipole modes, the system reduces to four physical modes with two dynamical modes and two shadowy modes.
Article
Astronomy & Astrophysics
Masato Minamitsuji, Antonio De Felice, Shinji Mukohyama, Michele Oliosi
Summary: In this study, static and spherically symmetric solutions are investigated in the minimal theory of bigravity (MTBG). It is found that a pair of Schwarzschild-de Sitter spacetimes with different cosmological constants and black hole masses is a solution in the self-accelerating branch of MTBG, but not in the normal branch. It is also shown that the Schwarzschild-de Sitter solutions can become compatible with the normal branch by using different coordinates. Furthermore, it is confirmed that the self-accelerating branch of MTBG admits static and spherically symmetric general relativity solutions with matter written in the spatially flat coordinates, including neutron stars with arbitrary matter equations of state. Finally, it is demonstrated that nontrivial solutions in the self-accelerating branch are given by the Schwarzschild-de Sitter metrics written in nonstandard coordinates.
Article
Astronomy & Astrophysics
Antonio De Felice, Shinji Mukohyama, Masroor C. Pookkillath
Summary: In this work, a class of extended minimal theories of massive gravity is introduced, which does not require the same cosmological solutions as the de Rham-Gabadadze-Tolley massive gravity. The theory is constructed to have only two degrees of freedom in the gravity sector, and the unwanted degrees of freedom are removed by adding constraints. The gravitational waves are the only propagating gravitational degrees of freedom that acquire a nontrivial mass. The theory's effective gravitational force is investigated by studying cosmological scalar perturbations. The class of models is further restricted by imposing certain conditions, leading to finite contributions of the Integrated Sachs-Wolfe (ISW) effect and the possibility for nontrivial modifications of gravity.
Article
Astronomy & Astrophysics
Antonio De Felice, Shinji Mukohyama, Masroor C. Pookkillath
Summary: Static, spherically symmetric solutions representing stars made of barotropic perfect fluid are studied in the context of two theories of type-II minimally modified gravity, VCDM and VCCDM. It is found that the solutions in V(C)CDM exactly coincide with the ones in GR.
Article
Astronomy & Astrophysics
Jose C. N. de Araujo, Antonio De Felice, Suresh Kumar, Rafael C. Nunes
Summary: The authors investigated the minimal theory of massive gravity (MTMG) with the Planck-cosmic microwave background (CMB) data for the first time and found that the MTMG model can provide solutions to tensions in observational data within the A cold dark matter cosmology. They also showed that the graviton in the MTMG scenario has a small, positive, non-zero mass and that the theory remains consistent with CMB observations, positioning it as a viable candidate among other modified gravity theories.
Article
Astronomy & Astrophysics
Nelson R. F. Braga, Octavio C. Junqueira
Summary: This study investigates the influence of rotation on the transition temperature of strongly interacting matter produced in non-central heavy ion collisions. By using a holographic description of an AdS black hole, the authors extend the analysis to the more realistic case where the matter spreads over a region around the rotational axis. The results show the coexistence of confined and deconfined phases and are consistent with the concept of local temperature in rotating frames developed by Tolman and Ehrenfest.
Article
Astronomy & Astrophysics
Bing Sun, Jiachen An, Zhoujian Cao
Summary: This paper investigates the effect of gravitational constant variation on the propagation of gravitational waves. By employing two analytical methods, the study finds that variations in the gravitational constant result in amplitude and phase corrections for gravitational waves, and the time variation of the gravitational constant can be constrained through the propagation of gravitational waves.
Article
Astronomy & Astrophysics
Abdellah Touati, Zaim Slimane
Summary: This letter presents the first study of Hawking radiation as a tunneling process within the framework of non-commutative gauge theory of gravity. The non-commutative Schwarzschild black hole is reconstructed using the Seiberg-Witten map and the star product. The emission spectrum of outgoing massless particles is computed using the quantum tunneling mechanism. The results reveal pure thermal radiation in the low-frequency scenario, but a deviation from pure thermal radiation in the high-frequency scenario due to energy conservation. It is also found that noncommutativity enhances the correlations between successively emitted particles.
Article
Astronomy & Astrophysics
Shahar Hod
Summary: The travel times of light signals between two antipodal points on a compact star's surface are calculated for two different trajectories. It is shown that, for highly dense stars, the longer trajectory along the surface may have a shorter travel time as measured by asymptotic observers. A critical value of the dimensionless density-area parameter is determined for constant density stars to distinguish cases where crossing through the star's center or following a semi-circular trajectory on the surface has a shorter travel time as measured by asymptotic observers.
