Science – Page 105

Twisted Disks, Shifting Signals: A New View of Black Hole Behavior

17.11.2025 by pricpr

$The transition from one quasi-periodic oscillation (QPO) type to another in X-ray binaries appears linked to a warping of the accretion disk, where a radius, $r_{b}$, marks the point beyond which the outer disk remains aligned, while within $r_{b}$ a warp is forced upon the cold accretion disk, altering the alignment angle of the hot flow and signaling a shift from type C to type B configurations.$

Researchers propose a unified model linking the diverse low-frequency oscillations observed in black hole X-ray binaries to the dynamics of warped accretion disks.

Untangling Time: A New Approach to Causal Discovery

17.11.2025 by pricpr

Functional magnetic resonance imaging data from distinct brain regions—specifically, $X_1$ from region 1 and $X_2$ from region 2—are susceptible to spurious correlations when an unobserved external interference, designated as $ZZ$, acts as a latent variable influencing the measurements.

Researchers have developed a novel method for identifying causal relationships in dynamic systems, even when hidden factors are at play.

Beyond Interactions: How Dissipation Can Birth Time Crystals

16.11.2025 by pricpr

New research reveals a surprising path to creating discrete time crystals – not through complex interactions, but through carefully harnessing environmental dissipation.

Shaping Light’s Quantum Noise

16.11.2025 by pricpr

The study demonstrates manipulation of optical path-dependent coherence—specifically, Hong-Ou-Mandel (HOM) dips—in the Langevin regime, achieving visibilities up to 0.851 through the strategic implementation of $SiO_2$ and $Ti/Au$ layers, and confirming theoretical predictions with measured spectra of heralded idler and signal photons despite inherent complexities of production environments.

Researchers have, for the first time, demonstrated controlled manipulation of quantum fluctuations generated through optical parametric down-conversion on an integrated chip.

Shadows of Doubt: Better Statistics for Quantum States

16.11.2025 by pricpr

Theoretical error bounds, as defined by the equation, are rigorously tested against the variability demonstrated by $1000$ bootstrap distributions, with performance assessed across varying values of $NN$.

A new approach leverages statistical resampling to unlock more accurate and reliable analysis of quantum systems, particularly for understanding rare events and managing risk.

Steering Quantum Coherence with Janus States

16.11.2025 by pricpr

$Cross-mode coherence, quantified through a full sweep of parameters $r$ and $\delta$, reveals the phase structure of the pair kernel and exposes a “Janus switch”—a transition between correlation amplification in single transverse modes and correlation suppression in joint modes—with the global minimum occurring at an antisymmetric setting of $(\pi, \pi)$.$

A new framework leveraging superposed squeezed states offers a pathway to control quantum correlations and enhance detector sensitivity in relativistic scenarios.

Beyond Unitary Evolution: A New Path for Quantum Simulation

16.11.2025 by pricpr

Researchers have developed a novel framework for simulating quantum systems that evolve beyond the standard rules of unitary dynamics, opening doors to more realistic and powerful quantum computations.

Hidden Correlations: A New Phase of Quantum Information

16.11.2025 by pricpr

$The study delineates a phase diagram for Holevo information, $χ({\cal E}_{{\rm PPE}_{R}})$, revealing its relationship to entanglement phases between subsystems, and establishes a boundary—differentiated through analytical calculations and numerical extrapolation—between measurement-visible and measurement-invisible regimes for tripartite Haar-random states across varying qubit partitions, as demonstrated by heatmap analysis and finite-size scaling data presented elsewhere.$

Researchers have discovered a distinct phase transition in the information content of quantum ensembles, revealing states where correlations exist despite being undetectable by standard measurements.

Harnessing Geometric Forces for Quantum Energy Transfer

15.11.2025 by pricpr

$Energy pumping into a driven system exhibits sensitivity to initial conditions and parameter ratios, as demonstrated by trajectories revealing variance influenced by the ratio $p/q=3/2$, standard deviation plots across different $p/q$ values, and comparisons between phase-averaged results and analytical calculations—all while maintaining consistent parameters of $\omega=0.4$, $\Delta=1$, $m=0.5$, $c=1/\sqrt{2}$, and $\delta\phi=\pi/2$.$

A new theoretical framework details a method for sustainably pumping energy in quantum systems by exploiting non-abelian Berry curvature and transitionless control techniques.

Decoding Quantum States for Molecular Modeling

15.11.2025 by pricpr

The shadow variational 2-RDM method, incorporating full 2-positivity constraints, demonstrates a relationship between computational budget—specifically, the total number of shots—and the achievable precision, as evidenced by the lowest 2-RDM eigenvalue, when contrasted with the Fermionic Classical Shadows approach applied to the H4 molecule in a minimal basis set.

A new approach to quantum state reconstruction promises more accurate and robust simulations of complex molecular systems on today’s noisy quantum hardware.