The Weight of Time: Limits on Microscopic Clock Accuracy
![For a given distribution, the variance exhibits an approximate power law relationship across a range of [latex]\mathcal{N}[/latex] values, remaining remarkably consistent-with fitted γ values of 0.490, 0.495, and 0.491 for ratios of [latex]n/\mathcal{N}[/latex] of 10%, 50%, and 90% respectively-and converging further toward ½ as [latex]\mathcal{N}[/latex] increases, indicating a predictable scaling behavior independent of the specific ratio within the studied range.](https://arxiv.org/html/2602.24177v1/2602.24177v1/ninetypercent.png)
New research establishes a fundamental trade-off between the precision of quantum clocks and the gravitational disturbance they create in spacetime.
Science
Taming Dirac’s Ghosts: A New View of Negative Energy States
![The study demonstrates distinct energy spectra for electrons and positrons, modeled by equations [latex] (24) [/latex] and [latex] (25) [/latex] respectively, highlighting fundamental differences in their energetic behavior.](https://arxiv.org/html/2602.23384v1/2602.23384v1/x3.png)
A new analysis resolves long-standing paradoxes within the Dirac equation by focusing exclusively on positive energy solutions, offering a refined foundation for relativistic quantum electrodynamics.
Hunting the Elusive Toponium: A New Approach at the LHC
![The study details distributions of [latex]\mathrm{t\bar{t}}[/latex] events-both those originating from top quark pairs alone and those combined with toponium contributions-across key angular and kinematic observables like [latex]\Delta R[/latex], [latex]\Delta \phi[/latex], [latex]p^{\star}[/latex], [latex]D^{(1)\mathrm{evt}}[/latex], [latex]\cos\theta^{\prime}[/latex], and [latex]\widetilde{M}^{\mathrm{evt}}\_{2}[/latex], normalized to an integrated luminosity of [latex]\mathcal{L}=140[/latex] fb$^{-1}$ at 13 TeV, demonstrating how subtle variations in event characteristics can reshape the apparent signal and potentially obscure the fundamental processes at play.](https://arxiv.org/html/2602.23426v1/2602.23426v1/figures/ttbar_Mtilde2.png)
Researchers are leveraging spin correlations and quantum information tools to sharpen the search for toponium, a fleeting bound state of top and antitop quarks, at the Large Hadron Collider.
Beyond Alloys: Mapping the Landscape of Complex Materials
![The approach establishes a multi-component featurization by assigning each atom a cutoff radius [latex]R_{cut}[/latex] and core exclusion radius [latex]R_{core}[/latex] sampled from distributions dependent on the chemical element, then maximizes the feature information entropy of the dataset augmented with candidate configurations to refine the spatial arrangement.](https://arxiv.org/html/2602.23489v1/2602.23489v1/x4.png)
A new modeling framework and comprehensive dataset are unlocking the potential of multi-elemental materials with unprecedented accuracy and predictive power.
Beyond Black Holes: Seeing the Universe’s Hidden Objects
![Numerical solutions demonstrate that for [latex]m=2[/latex] and [latex]m=4[/latex], the behavior of [latex]h[/latex], [latex]\bar{\phi} - \bar{\phi}_0[/latex], and [latex]{\cal M}/M_0[/latex] as functions of [latex]r/r_0[/latex] exhibits qualitative similarities, particularly in the minima of [latex]h[/latex], despite slight variations in asymptotic values of [latex]\bar{\phi}[/latex], and occurs with parameter choices where α is just below the critical value necessary for photon ring formation.](https://arxiv.org/html/2602.23657v1/2602.23657v1/x4.png)
New research explores how exotic compact objects, supported by dark matter interactions, could reveal themselves through unique gravitational lensing effects.
Beyond Big O: Pinpointing Algorithm Bottlenecks
A new analysis framework reveals how input parameters directly influence computational cost, moving beyond simple complexity classifications.
Hunting Sub-GeV Dark Matter with Superfluid Helium
A new analysis details the projected reach of the QUEST-DMC experiment in the search for light dark matter particles interacting with terrestrial detectors.
Holographic Symmetry: Unveiling Hidden Dynamics at the Boundary
New research explores how continuous symmetries manifest in holographic systems, revealing a deep connection between boundary operators and the dynamics of branes in anti-de Sitter space.
Confining the Quantum Realm: A New Look at Non-Abelian Gauge Theory
![The study quantifies the Lüscher term’s contribution to potential energy-a finite-size effect in lattice gauge theory-across varying lattice widths [latex]N_x[/latex] of 55, 44, and 33, demonstrating its dependence on the string tension σ and a constant [latex]c[/latex], calculated as the difference between the potential [latex]V(N_y)[/latex] and [latex]σ N_y[/latex].](https://arxiv.org/html/2602.23213v1/2602.23213v1/x64.png)
Researchers have successfully simulated a complex quantum system, providing new insights into the behavior of non-Abelian gauge theories in two dimensions.
Molecular Choreography: Sculpting Quantum Landscapes with Polar Molecules
![Through manipulation of microwave fields, polar molecules exhibit a deformed Fermi surface-an ellipsoidal momentum distribution elongated along attractive interaction axes and counteracted by kinetic pressure-with the degree of deformation, quantified by [latex]\Delta_{xy}=\sigma_{x}/\sigma_{y}-1[/latex], predictably modulated by ellipticity and Rabi frequency, and visualized through analysis of absorption images revealing quadrupolar deformation residuals when compared to circular fits and rotated copies of the molecular cloud.](https://arxiv.org/html/2602.22447v1/2602.22447v1/x1.png)
Researchers have directly observed how interactions between ultracold polar molecules can be used to reshape the fundamental quantum properties of a gas, opening new avenues for exploring exotic states of matter.