Article
Astronomy & Astrophysics
Geova Alencar, Matheus Nilton
Summary: This paper analyzes the Schwarzschild-like wormhole in the Asymptotically Safe Gravity scenario, examining the radial energy conditions and potential types of cosmologic matter present. The study shows that in specific cases, the energy conditions are satisfied at the throat, but not in general, and that phantom-like matter may exist in all scenarios. Quantum gravity corrections due to ASG are found to imply the presence of phantom-like matter for both Schwarzschild and Schwarzschild-like wormholes, suggesting a consistent presence of phantom fluid in this context.
Article
Astronomy & Astrophysics
G. Alencar, V. B. Bezerra, C. R. Muniz, H. S. Vieira
Summary: This paper investigates the simplest wormhole solution in the context of asymptotically safe gravity at the Planck scale. It is found that asymptotic safety guarantees the Ellis-Bronnikov wormhole can satisfy radial energy conditions and requires exotic sources of matter to generate the wormhole spacetime. Furthermore, the paper speculates on the presence of phantom-like matter in wormholes in the ASG context or more general quantum gravity scenarios.
Article
Astronomy & Astrophysics
M. Nilton, J. Furtado, G. Alencar
Summary: In this paper, we investigate the traversability of a wormhole in the context of asymptotically safe gravity (ASG) for both spherical and pseudospherical cases. We analyze the throat of the wormhole using a specific cutoff function and generalize the previous study by considering a position-dependent classical state parameter and an ASG improvement of the source. Our findings suggest that traversability of the wormhole is highly dependent on its parameters and the type of matter used.
Article
Astronomy & Astrophysics
Michele Arzano, Andrea Bevilacqua, Jerzy Kowalski-Glikman, Giacomo Rosati, Josua Unger
Summary: In this work, a construction of kappa-deformed complex scalar field theory is presented to investigate the impact of deformation on discrete symmetries and CPT invariance. The study reveals that particles and antiparticles are characterized by different mass-shell constraints, leading to a subtle departure from CPT invariance. The remaining part of the work focuses on the detailed description of the action of deformed Poincare and discrete symmetries on the complex field.
Article
Astronomy & Astrophysics
J. Chojnacki, J. Krajecka, J. H. Kwapisz, O. Slowik, A. Strag
Summary: This article explores the relationship between eternal inflation and the asymptotic safety hypothesis in other approaches to quantum gravity. It reveals that there is no tension between eternal inflation and asymptotic safety in both the matter and gravitational sectors, contrary to string theory. Additionally, it suggests that eternal inflation is not possible within the range of applicability of effective field quantum gravity theory.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Biao Zhou, Askar B. Abdikamalov, Dimitry Ayzenberg, Cosimo Bambi, Sourabh Nampalliwar, Ashutosh Tripathi
Summary: Asymptotically safe quantum gravity theory builds on the framework of quantum field theory, with a new rotating black hole metric proposed to extend its applications. X-ray reflection spectroscopy is used to observe and test the theory.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Particles & Fields
Christian Pfeifer, Jose Javier Relancio
Summary: This article presents a systematic analysis of how deformed relativistic kinematics can be lifted to curved spacetimes in terms of a self-consistent cotangent bundle geometry. The analysis shows that momentum space metrics can be consistently lifted to curved spacetimes if they satisfy certain conditions. The article also discusses the connection between this construction and non-commutative spacetimes.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Multidisciplinary
Alessio Baldazzi, Kevin Falls, Renata Ferrero
Summary: This paper presents an approach to compute the renormalisation group flow of relational observables in quantum gravity, with the application example of four scalar fields coupled to gravity. The approach is applicable to a wide range of relational observables in different physical coordinate systems, and evaluates their scaling dimensions at fixed points.
Article
Astronomy & Astrophysics
Oem Trivedi, Maxim Khlopov
Summary: This study explores the formation of cosmological singularities in asymptotically safe cosmology using renormalization group approaches. It discovers special conditions and forms of cosmological singularities in this cosmology, which differ significantly from standard cosmology and do not require free parameters. Additionally, conventional singularity removal methods are ineffective in this cosmology.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Physics, Particles & Fields
Kamila Kowalska, Enrico Maria Sessolo, Yasuhiro Yamamoto
Summary: By utilizing the framework of asymptotically safe quantum gravity, predictions for scalar leptoquark solutions to the b.s and b.c flavor anomalies were derived. The presence of an interactive UV fixed point in the system imposed boundary conditions at the Planck scale, narrowing down the allowed leptoquark mass range. Gravity-driven solutions for b.s anomalies predict a leptoquark mass of 4-7 TeV, within reach of future high-energy colliders, while solutions for b.c anomalies predict a leptoquark mass at the edge of current LHC bounds. Complementary signatures are expected in flavor observables.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Multidisciplinary
M. Nilton, J. Furtado, G. Alencar, R. R. Landim
Summary: In this study, we examine a type of wormhole solutions known as generalized Ellis-Bronnikov wormholes in the framework of asymptotically safe gravity (ASG). These solutions are characterized by two parameters: an even number n and the wormhole throat radius rt. By utilizing three curvature scalars in the ASG approach, namely, the Ricci scalar, squared Ricci, and the Kretschmann scalar, we investigate the nature of matter in the throat and nearby regions of these generalized solutions with n > 2. Our findings reveal that the ASG only introduces corrections in the matter at the throat for the case of n = 4. Furthermore, we demonstrate that exotic matter is always required for the squared Ricci and the Kretschmann cases, whereas for the Ricci scalar case, ordinary matter is permissible at the throat. Consequently, the generalized Ellis-Bronnikov wormhole offers the possibility of having ordinary matter at the throat within the context of asymptotically safe gravity.
Article
Astronomy & Astrophysics
Gustavo P. de Brito, Antonio D. Pereira, Arthur F. Vieira
Summary: The renormalization group flow of unimodular quantum gravity was studied with different truncations of the effective action, searching for nontrivial fixed-point solutions for polynomial expansions. The system included beta functions for gravitational couplings, anomalous dimensions of graviton and ghosts, and investigated the impact of different endomorphism parameter choices on fixed-point structure. Evidence for nontrivial fixed points was found, with the f(R) truncation showing better convergence properties, and compatibility with the Standard Model and its extensions was explored when matter fields were included.
Article
Physics, Particles & Fields
Fabian Wagner
Summary: The minimal and maximal uncertainties of position measurements are considered to be important characteristics of low-energy quantum and classical gravity. This study shows that the Generalized Extended Uncertainty Principle can be described in terms of quantum dynamics on a general curved cotangent manifold, with the curvature tensors being related to the noncommutativity of coordinates and momenta. The covariance of the approach leads to interesting subclasses of noncommutative geometries and enables the derivation of anisotropically deformed uncertainty relations from general background geometries.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Mathematical
Jose Javier Relancio
Summary: Doubly special relativity has been studied as a way to explore residual effects of a quantum gravity theory beyond special relativity. It extends the relativistic principles by introducing the Planck energy as an additional invariant alongside the speed of light. Current research focuses on the connection between deformed kinematics and curved momentum space, deriving such kinematics from geometric ingredients.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2022)
Article
Astronomy & Astrophysics
Jesse Daas, Wouter Oosters, Frank Saueressig, Jian Wang
Summary: By setting up a consistent background field formalism, we conducted a detailed study on the renormalization group flow of gravity coupled to Nf Dirac fermions, identifying two infinite families of interacting RG fixed points. These fixed points correspond to quasi-chiral and non-chiral fixed points, showing potential for high-energy completion and becoming weakly coupled in the large Nf-limit.
Article
History & Philosophy Of Science
Sabine Hossenfelder
Summary: This paper critically analyzes the arguments from finetuning and naturalness in particle physics and cosmology, identifying reasons why they are not scientifically relevant. It also discusses other numerological coincidences and their problems.
Article
Astronomy & Astrophysics
Xavier Calmet, Folkert Kuipers
Summary: In this letter, we demonstrate that quantum gravity imposes limitations on the masses of dark matter candidates, determined by their spins and interactions in the dark matter sector. For singlet scalar dark matter, the mass range lies between 10(-3) eV and 10(7) eV, with the lower bound from restrictions on fifth force interactions and the upper bound from the dark matter candidate's lifetime.
Article
Astronomy & Astrophysics
Xavier Calmet, Folkert Kuipers
Summary: This essay demonstrates that quantum gravity and the spin-statistics theorem have interesting implications for dark matter candidates, imposing lower bounds on bosonic and fermionic masses, as well as influencing the decay of dark matter particles. By comparing their lifetimes with the age of the universe, upper bounds on their masses are determined.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2021)
Article
Physics, Multidisciplinary
Michael te Vrugt, Sabine Hossenfelder, Raphael Wittkowski
Summary: This study extends the Mori-Zwanzig projection operator formalism to address the challenge of coarse-graining in general relativity, deriving a new dynamic equation for the Hubble parameter using the Buchert equations. The effects of averaging are captured through a memory function, leading to an empirical prediction for cosmic jerk.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Xavier Calmet, Stephen D. H. Hsu
Summary: The precision of angular measurements or rotations is limited by fundamental constraints from quantum mechanics and general relativity, with a fundamental limitation in Planck units indicating that spin states with sufficiently small differences in rotation cannot be experimentally distinguished. This raises important implications for finitism and questions whether physics requires infinity or a continuum.
Article
Astronomy & Astrophysics
Xavier Calmet, Nathaniel Sherrill
Summary: This paper demonstrates that atom interferometer experiments, such as MAGIS, AION, and AEDGE, have the potential to probe both very light dark matter models and quantum gravity. The linear coupling between a singlet scalar dark matter particle and electrons or photons is ruled out by current understanding of quantum gravity and torsion pendulum experiments. However, the quadratic coupling of scalar dark matter with electrons and photons has a large viable parameter space that can be explored by these atom interferometers. The implications for quantum gravity searches are discussed.
Article
Physics, Multidisciplinary
S. Donadi, S. Hossenfelder
Summary: A new path-integral approach over Hilbert space is proposed, which accurately reproduces quantum mechanics by optimizing the generating functional under a variation of the final state. The advantage of this method is that entangled states are directly included in the paths, and the generating functional can be modified to incorporate wave-function collapse.
Article
Astronomy & Astrophysics
T. Mistele, S. McGaugh, S. Hossenfelder
Summary: This study made rotation curve fits using the superfluid dark matter model and evaluated the relationship between the fits, stellar mass-to-light ratios, and the resemblance to MOND. The results showed that the mass-to-light ratios obtained with superfluid dark matter are generally reasonable, but they exhibit an unnatural dependence on galaxy size. Additionally, when the fits were forced to resemble MOND, there was tension between the total dark matter mass and gravitational lensing data.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Xavier Calmet, Stephen D. H. Hsu
Summary: This study demonstrates that the quantum state of the graviton field outside a black hole horizon can carry information about the internal state of the hole, allowing for unitary evaporation. Specifically, the final radiation state is a complex superposition that linearly depends on the initial black hole state. Under time reversal, the radiation state can evolve back to the original black hole quantum state. The information paradox, described on a fixed semiclassical geometry, only refers to a small subset of the evaporation Hilbert space and does not exclude overall unitarity.
Article
Multidisciplinary Sciences
Jonte R. Hance, Sabine Hossenfelder
Summary: This article analyzes the relationship between the wave function and the possible measurement results in quantum mechanics, and proposes a more useful explanation of this relationship. It also discusses the issue of statistical independence violations in some common interpretations and theories, and introduces the concept of superdeterministic or retrocausal. Finally, it explains how this interpretation helps make sense of some puzzling phenomena in quantum mechanics.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Review
Physics, Multidisciplinary
Jonte R. Hance, Sabine Hossenfelder
Summary: We summarize various aspects of the measurement problem in quantum mechanics, emphasizing that it is a real problem in need of a solution. We argue that current interpretations of quantum mechanics cannot provide a solution as they are only interpretations and not extensions of the theory. Additionally, we speculate on the potential benefits of solving the measurement problem.
JOURNAL OF PHYSICS COMMUNICATIONS
(2022)
Article
Optics
Sandro Donadi, Sabine Hossenfelder
Summary: The local, deterministic toy model for quantum mechanics makes the same predictions as quantum mechanics when averaged over hidden variables. The dynamics depend on the settings of the measurement device at the time of detection but not on how those settings were chosen. Furthermore, the model is neither fine tuned nor allows for superluminal signaling.
Article
Astronomy & Astrophysics
Xavier Calmet, Folkert Kuipers
Summary: In this study, quantum gravitational corrections to black hole entropy were calculated within an effective field theory approach. Second and a subset of third order curvature corrections to the entropy were examined, revealing new issues at third order previously unexplored in the literature. These corrections, particularly at third order, have significant implications on the Schwarzschild metric, affecting horizon radius and temperature, which are crucial considerations in entropy calculations.
Correction
Business, Finance
Xavier Calmet, Nathaniel Wiesendanger Shaw
JOURNAL OF FUTURES MARKETS
(2021)
Article
Astronomy & Astrophysics
Xavier Calmet, Roberto Casadio, Folkert Kuipers
