Institució Catalana de Recerca i Estudis Avançats

Scalable ground-state certification of quantum spin systems via structured noncommutative polynomial optimization

A fundamental challenge in quantum physics is determining the ground-state properties of many-body systems. Whereas standard variational approaches posit a wave-function ansatz and minimize over the possible states expressible by that ansatz, the problem can alternatively be form...

Second‐Sphere Aromatic Substitutions That Tune H‐Atom Transfer Reactivity Observed for a Series of S = 1 Nonheme Fe IV =O Complexes: An Enthalpy‐Entropy Compensation Effect

ABSTRACT Synthetic nonheme Fe IV ═O complexes reported thus far often have S = 1 ground states, demonstrating markedly lower oxidative reactivity in C─H bond breakage compared to their S = 2 counterparts. Recently, we have identified that incorporating cycloalkyl groups into the...

The gene-regulatory evolution of the human skeleton

Abstract Skeletal modifications were central to human evolution, enabling adaptations for bipedalism, large cranial vaults and childbirth 1 . Despite their importance, the genetic changes that gave rise to the unique human form remain mostly unknown 2 . Here we systematically map...

Microsecond-pulsed nanocalorimetry: a scalable approach for ultrasensitive heat capacity measurements

Abstract We introduce a nanocalorimetric technique based on microsecond-pulsed heating (µs-PHnC) that enables high-sensitivity, quasi-isothermal heat capacity measurements on nanoscale samples. Such resolution is critical for exploring thermodynamic signatures in low-dimensional...

An experimental study of fuel use at the microscale: Plant and dung microfossil indicators from combustion installations

This paper addresses the contribution of experimentally-produced combustion installations to microarchaeological research on the identification, characterization and taphonomy of fuel materials as valuable past traces of fire use. Recent studies have investigated the taphonomy of...

Faunal Evidence and the Duration of Occupation: A Statistical Approach to Neanderthal Archaeological Sites

Abstract The duration of Neanderthal occupations of caves and rock shelters is one of the most debated issues in prehistoric archaeology. Several disciplines, including lithic analysis, micromorphology, zooarchaeology, taphonomy, and spatial archaeology, have proposed criteria to...

Into the woods of ancient Corinth: wood charcoal analysis & human-woodland associations in Hellenistic and early Roman Greece

This paper explores the historical periods of Hellenistic and Early Roman Greece, which brought important changes to the region during the second half of the 1st millennium BCE. While these periods hold great historical and cultural importance, the understanding of how individual...

Second-Sphere Protonation Imparts a Biologically Relevant Potential Shift in a Chlorophyll Model Compound

Abstract Electrostatic protein-pigment interactions have been implicated in tuning the electron transfer chemistry of chlorophylls in vivo; however, these effects are difficult to probe directly, leading to a dearth of experimental data that limits our understanding. Herein, we r...

From past, persisting, and consolidating ecologies of segregation to ecologies of repair

Across the United States and Europe, urban and periurban spaces have historically been shaped by land dispossession and enclosure that systematically exclude marginalized, non-White communities from the benefits of society, including access to nature. These dynamics, which have p...

Heights of complete intersections in toric varieties

The height of a toric variety and that of its hypersurfaces can be expressed in convex-analytic terms as an adelic sum of mixed integrals of their roof functions and duals of their Ronkin functions. Here we extend these results to the 2 -codimensional situation by presenting a li...

Pneumococcal population structure influences the effects of air pollution on invasive disease risk in South Africa

Abstract Streptococcus pneumoniae is highly diverse, comprising over 100 serotypes and hundreds of genomic lineages amid widespread vaccination. While it can cause invasive pneumococcal disease (IPD) which exhibits pronounced seasonal spikes, the interplay between pneumococcal di...

Lebanese faunal legacy collections uncover 400,000 years of woodland resilience and distinct hominin ecological strategies

Abstract The Levant is a key biogeographic corridor, yet historical instability has limited research creating a polarization toward its southern region. To address this geographical bias, we reassessed three legacy faunal collections from Lebanon: Naame, Nahr Ibrahim, and Ras el-...

Black holes and causal nonlinear electrodynamics

A bstract For generic theories of nonlinear electrodynamics (NLED) we investigate the implications of (a)causality on spherically-symmetric solutions of the Einstein-NLED equations that are asymptotic to a Reissner-Nordström (RN) spacetime. Equal-charge dyonic RN black holes are...

Synergistic Surface/Bulk Charge Modulation Enables Record-Level Photocurrent in Hematite Photoanodes without Co-Catalysts for Photoelectrochemical Water Splitting

Abstract Hematite (α-Fe2O3) photoanodes are limited by poor bulk conductivity and severe surface recombination, which hinder their photoelectrochemical (PEC) water-splitting activity. We demonstrate that a simple, rapid microwave-sintering (RMS) route simultaneously incorporates...

Quantifying atmospheric and land drivers of hot temperature extremes through explainable Artificial Intelligence

Abstract. Different drivers have been shown to play a central role in modulating the occurrence and intensity of summer temperature extremes, yet their individual contributions remain difficult to quantify. In this study, we develop an explainable machine‐learning framework to di...

Multilingual large language models do not comprehend all natural languages to equal degrees

Abstract Large Language Models (LLMs) play a critical role in how humans access information. While their core functionality relies on the ability to comprehend written requests, our understanding of this ability is currently constrained, because most benchmarks evaluate LLMs in h...

Mapping the nuclear environments of extreme coronal line emitting galaxies

Abstract Extreme coronal line emitters (ECLEs) are a rare class of galactic nuclei exhibiting unusually strong high-ionisation forbidden emission lines, and several ECLEs have been linked to tidal disruption events (TDEs). In this work, we compile and analyse optical spectra of 3...

Humans: Intertwined with life and the basic elements in the Anthropocene biosphere

Abstract The notion of people and nature as intertwined and embedded in the biosphere is gaining traction in contemporary scientific discourses. But what does it mean for a human being to be intertwined? Here, we explore this question through two lenses: looking at the human body...

Astrocytic PI3Kα controls synaptic plasticity and cognitive function via serine metabolism

Astrocytes modulate neuronal activity by gliotransmission and through metabolic regulation, yet the relationship between these functions remains poorly understood. Here we show that phosphatidylinositol 3-kinase (PI3K) signaling in astrocytes controls synaptic plasticity and memo...

Self-sustained, out-of-equilibrium inflation

A bstract We use holography to study dS-invariant states of non-conformal, strongly coupled quantum field theories in four-dimensional de Sitter space. We show that out-of-equilibrium effects can sustain the exponential inflation within the regime of validity of semiclassical gra...