Beyond Einstein: Mapping Neutron Stars to Probe Modified Gravity
![Neutron star parameters-radius, tidal deformability, and compactness-exhibit quantifiable relationships with mass, as determined through a Bayesian framework incorporating astrophysical observations and expressed as 95% confidence intervals for [latex] \text{radius}_{RR} [/latex] (km), Λ, and [latex] M/R [/latex] as functions of mass [latex] M_{\odot} [/latex].](https://arxiv.org/html/2601.16227v1/x4.png)
New research utilizes observations of neutron stars to test alternative theories of gravity, specifically exploring the viability of f(Q) gravity.
Science
Echoes from the Cosmos: Constraining Neutron Star Interiors
New research explores how observations of ‘twin stars’-pairs of neutron stars with similar masses but differing radii-are refining our understanding of the extreme matter within these cosmic objects.
Pinpointing Particle Interactions: A New Look at Pion Production
![The measured cross section of electron-positron annihilation into pion pairs-a fundamental process in particle physics-demonstrates a consistent relationship to the reduced energy [latex]\sqrt{s^{\prime}}[/latex], and notably aligns with, yet refines, previous findings from the 2009 BABAR experiment, suggesting a robust understanding of this interaction.](https://arxiv.org/html/2601.16587v1/x6.png)
The BABAR experiment delivers a high-precision measurement of how electron-positron collisions create pion pairs, refining calculations crucial for understanding fundamental particle properties.
Untangling the Exotic: Many-Body Physics Reveals Robust Anyon Braiding
![The study positions four quantum harmonic oscillators - designated QHs11, 44, 22, and 33 - at precisely calculated distances from the origin: QHs11 and 44 initially reside at a distance of [latex]r = R/3[/latex], positioned at polar angles of 0 and π, while QHs22 and 33 are fixed at [latex]r = 2R/3[/latex], also at angles of 0 and π, where [latex]R = \sqrt{2N/\nu}[/latex] defines the scaling factor based on the system’s inherent parameters.](https://arxiv.org/html/2601.16819v1/x2.png)
New research demonstrates a powerful method for simulating and verifying non-Abelian anyon behavior in complex many-body systems, paving the way for advancements in topological quantum computation.
Entanglement’s Hidden Currents: Polarization, Anomalies, and Beyond
New research connects quantum entanglement, the axial anomaly, and polarization phenomena, offering a framework for understanding non-causal effects in extreme physical environments.
Quantum Fields and the Fate of the Universe
New research applies advanced quantization techniques to k-essence cosmology, offering insights into the universe’s earliest moments and its ultimate destiny.
Hunting for Dark Matter with Atomic Clocks in Space
![Sensitivity projections for detecting dark matter interactions, achieved through comparisons between space- and ground-based clocks, demonstrate that missions like ACES, those operating on the International Space Station, and the proposed FOCOS mission can probe a range of dark matter masses-extending beyond current bounds established by MICROSCOPE, SNG, and BBN-with sensitivity limited by factors such as atmospheric reflection, satellite shielding, and the breakdown of low-momentum approximations at higher masses, as determined by fractional phase and frequency uncertainties of [latex]\delta t / \Delta t = 7 \times 10^{-{17}}[/latex] and stability parameters of [latex]\sigma_{y}(10^{6})[/latex] and [latex]\sigma_{y}(10^{7})[/latex].](https://arxiv.org/html/2601.16259v1/x6.png)
A new approach proposes leveraging the precision of orbiting quantum clocks to detect the elusive influence of ultralight dark matter on the fabric of spacetime.
Beyond the Lab: How Nations Are Building a Quantum Future
A new analysis of global quantum strategies reveals a clear pivot from basic research to practical applications and economic development.
Beyond CARMA: Building Complex Processes from Lévy Noise
![The correlation functions of supCAR(2)(2)-III processes demonstrate a transition in behavior based on shape parameters; when [latex]\alpha + 3 \in (3,4][/latex], these processes exhibit non-oscillatory long-range dependence, but as the shape parameter increases beyond this range, oscillations emerge, indicating a shift in the underlying dynamic characteristics.](https://arxiv.org/html/2601.15796v1/x4.png)
This review introduces supCARMA processes-superpositions of continuous-time autoregressive moving average models driven by Lévy processes-and details their theoretical properties.
Beyond Bundles: A Formal Framework for Differential Geometry
This review introduces a powerful, category-theoretic approach to differential objects, connections, and bundles, extending classical concepts to broader mathematical settings.