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A trichotomy for hitting times and escape rates for a class of unimodal maps
Get PDFFunding: M.D. was partially supported by NSF grants DMS 2055070 and DMS 2350079. M.T. was partially supported by the FCT (Fundação para a Ciência e a Tecnologia) project 2022.07167.PTDC.We consider local escape rates and hitting time statistics for unimodal interval maps of Misiurewicz–Thurston type. We prove that for any point z in the interval, there is a local escape rate and hitting time statistics that is one of three types. While it is key that we cover all points z, the particular interest here is when z is periodic and in the postcritical orbit that yields the third part of the trichotomy. We also prove generalized asymptotic escape rates of the form first shown by Bruin, Demers and Todd.Peer reviewe
JA-TN: pick-and-place towel shaping from crumpled states based on TransporterNet with joint-probability action inference
Get PDFTowel manipulation is a crucial step towards more general cloth manipulation. However, folding a towel from an arbitrarily crumpled state and recovering from a failed folding step remain critical challenges in robotics. We propose joint-probability action inference JA-TN, as a way to improve TransporterNet’s operational efficiency; to our knowledge, this is the first single data-driven policy to achieve various types of folding from most crumpled states. We present three benchmark domains with a set of shaping tasks and the corresponding oracle policies to facilitate the further development of the field. We also present a simulation-to-reality transfer procedure for vision-based deep learning controllers by processing and augmenting RGB and/or depth images. We also demonstrate JA-TN’s ability to integrate with a real camera and a UR3e robot arm, showcasing the method’s applicability to real-world tasks
Eleven new transiting brown dwarfs and very low mass stars from TESS
Get PDFFunding: The authors acknowledge financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/501100011033 and the ERDF “A way of making Europe” through project PID2021-125627OB-C32, and from the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrofisica de Canarias. D.R.C. and C.A.C. acknowledge partial support from NASA grant 18-2XRP18_2-0007. This work is partly supported by JSPS KAKENHI grant No. JP24H00017, JP24K00689 and JSPS Bilateral Program Number JPJSBP120249910. N.V. is supported by the NASA FINESST program. The postdoctoral fellowship of K.B. is funded by F.R.S.-FNRS grant T.0109.20 and by the Francqui Foundation. K.A.C. and C.N.W. acknowledge support from the TESS mission via subaward s3449 from MIT. I.A.S. acknowledges the support of M.V. Lomonosov Moscow State University Program of Development. F.M. acknowledge support from the Agencia Estatal de Investigación del Ministerio de Ciencia, Innovación y Universidades (MCIU/AEI) through grant PID2023-152906NA-I00. L.M. acknowledges financial contribution from PRIN MUR 2022 project 2022J4H55R. T.F.’s work is supported by the French National Research Agency in the framework of the Investissements d’Avenir program (ANR-15-IDEX-02), through the funding of the “Origin of Life” project of the Grenoble-Alpes University.We present the discovery of 11 new transiting brown dwarfs (BDs) and low-mass M dwarfs from NASA’s Transiting Exoplanet Survey Satellite (TESS) mission: TOI-2844, TOI-3122, TOI-3577, TOI-3755, TOI-4462, TOI-4635, TOI-4737, TOI-4759, TOI-5240, TOI-5467, and TOI-5882. They consist of five BD companions and six very-low-mass stellar companions ranging in mass from 25 MJ to 128 MJ. We used a combination of photometric time-series, spectroscopic, and high-resolution imaging follow-up as a part of the TESS Follow-up Observing Program (or TFOP) to characterize each system. With over 50 transiting BDs confirmed, we now have a large enough sample to directly test different formation and evolutionary scenarios. We provide a renewed perspective on the transiting “brown dwarf desert” and its role in differentiating between planetary and stellar formation mechanisms. Our analysis of the eccentricity distribution for the transiting BD sample does not support previous claims of a transition between planetary and stellar formation at ∼42 MJ. We also contribute a first look into the metallicity distribution of transiting companions in the range 7–150 MJ, showing that this does not support a ∼42 MJ transition too. Finally, we also detect a significant lithium absorption feature in one of the BD hosts (TOI-5882). However, we determine that the host star is likely old based on rotation, kinematic, and photometric measurements. We therefore claim that TOI-5882 may be a candidate for planetary engulfment.Peer reviewe
Observable-enriched entanglement
Get PDFFunding: This research was supported in part by the National Science Foundation under Grants No. NSF PHY-1748958 and No. PHY-2309135, and undertaken in part at the Aspen Center for Physics, which is supported by National Science Foundation Grant No. PHY-2210452.We introduce methods of characterizing entanglement on the example of the quantum skyrmion Hall effect, in which entanglement measures are enriched by the matrix representations of operators for observables. These observable operator matrix representations can enrich the partial trace over subsets of a system's degrees of freedom, yielding reduced density matrices useful in computing various measures of entanglement, which also preserve the observable expectation value. We focus here on applying these methods to compute observable-enriched entanglement spectra, unveiling bulk-boundary correspondences of canonical four-band models for topological skyrmion phases and their connection to simpler forms of bulk-boundary correspondence. Given the fundamental roles entanglement signatures and observables play in the study of quantum systems and the fundamental generalization of the interpretation and treatment of spin within the framework of the quantum skyrmion Hall effect, concepts of observable-enriched entanglement introduced here are broadly applicable to myriad problems of quantum systems.Peer reviewe
It matters where the heavy atom is placed : optimizing the spin-orbital coupling in multiresonant TADF (MR-TADF) emitters and its impact on OLED performance
Get PDFFunding: The study in China was supported by the National Natural Science Foundation of China (Grant Nos. 52130304, 52422309, and 52373193), the National Key Research & Development Program of China (Grant Nos. 2020YFA0714601, 2020YFA0714604), the Science and Technology Program of Suzhou (Grant No. ZXL2022490), Suzhou Key Laboratory of Functional Nano & Soft Materials, Collaborative Innovation Center of Suzhou Nano Science & Technology, the 111 Project. D.C. thanks the support from China Postdoctoral Science Foundation (Grant No. 2022TQ0227) and Natural Science Foundation of Jiangsu Province, China (Grant No. BK20230508). In the UK, this project has received funding from the Engineering and Physical Sciences Research Council for support (EP/R035164/1, EP/W007517/1, EP/Z535291/1).This study explores the impact of the regioisomerism of a heavy chalcogen atom on the photophysical properties of multi-resonant thermally activated delayed fluorescence (MR-TADF) materials. We synthesized two pairs of isomeric MR-TADF emitters containing different benzothienocarbazole moieties, tDPABT1B/tDPABT2B and tCzBT1B/tCzBT2B. Theoretical calculations indicate that tDPABT2B and tCzBT2B possess higher spin-orbital coupling values (0.27 and 0.60 cm⁻¹) compared to their respective isomers. The photophysical study reveals that tDPABT2B and tCzBT2B have twofold faster reverse intersystem crossing rate constants of 0.5 × 10⁵ and 2.7 × 10⁵ s⁻¹, respectively, than their isomeric counterparts. The sensitizer-free organic light-emitting diodes (OLEDs) with tCzBT1B and tCzBT2B exhibited green emissions [CIE coordinates of (0.12, 0.54)] and showed high maximum external quantum efficiencies (EQEmax) of 34.9% and 34.3%, respectively. Notably, the device with tCzBT2B demonstrated a reduced efficiency roll-off (34% decrease at 1000 cd cm⁻²) compared to that with tCzBT1B (48% decrease at 1000 cd cm⁻²), highlighting the distinct benefits and importance of the regiochemistry of the heavy atom in contributing to an enhancing device performance.Peer reviewe
Contemporaneous crust-derived I- and S-type granite magmatism and normal faulting on Tinos, Delos, and Naxos, Greece : constraints on Aegean orogenic collapse
No full textFunding: This work formed part of T.N. Lamont’s doctorate, funded by the Natural Environment Research Council (NERC; NE/L0021612/1). Analytical work was funded by NERC Isotope Geosciences Facilities Steering Committee (NIGFSC) grant IP-1597-1115. We would like to sincerely thank the Department of Earth Sciences, University of Oxford for covering publication costs.Granitoids of varying mineralogy are exposed on the Cycladic islands of Greece; they include both hornblende-bearing I-type granites and garnet ± muscovite−bearing S-type granites, suggesting heterogeneous magma sources. In this contribution, we present new field observations, major- and trace-element geochemistry, Sr-Nd isotopes, and U-Pb geochronology of granitoids from Tinos, Delos, and Naxos that provide insight into these magma sources, along with the timing of adjacent extensional structures. I-type (biotite and hornblende-biotite) granites have initial 87Sr/86Sr = 0.70956−0.71065 and εNd(t) = −6.3 to −9.3, and S-type (garnet ± tourmaline-muscovite) leucogranites have overlapping initial εNd(t) = −7.5 to −10.1, with initial 87Sr/86Sr values overlapping as well as extending to higher values (0.70621−0.73180). These isotope signatures are comparable to those of the Variscan-age Cycladic basement, but not the Hellenic arc. We suggest that both I- and S-type granites were derived via crustal anatexis of variable sources, dominantly metaigneous and metasedimentary, respectively, during the climax of Barrovian metamorphism between ca. 17 and 12 Ma, and critically, they are not related to the Hellenic subduction zone. I-type granitoids were likely derived from dehydration melting of igneous Variscan- or Cadomian-aged basement protoliths, whereas S-type leucogranites formed by muscovite dehydration melting of sedimentary protoliths. Top-to-the-(N)NE shear zones on Naxos and Tinos were active from ca. 20 to 15 Ma and are folded and cut by later low- and high-angle normal faults. S-type leucogranites at Livada Bay, Tinos, dated at ca. 14 Ma, are cut by domino-style normal faults, placing a maximum age on the timing of extension. This is similar to ca. 15−14 Ma dates from NNE-SSW horizontally boudinaged S-type granites on Naxos. We propose that the concurrent intrusion of both I- and S-type granitoids with the onset of normal faulting marked the transition from an overall compressional to an extensional stress field associated with orogenic collapse at ca. 15 Ma.Peer reviewe
Drifting past policy coherence? Rhetoric and realities of the Mexican Sembrando Vida program’s sustainability goals
Get PDFFunding: This research was carried out during the First Author’s postdoctoral research [CVU number 292956] funded by the Consejo Nacional de Ciencia y Tecnologia [CONACYT] Mexico.Global and interconnected sustainability challenges require systems thinking and policy coherence to support bold and coordinated action. To chart a course for action, the UN Sustainable Development Goals (SDGs) provide a suite of targets across international and national levels. Here, we explore intentions and contributions over time of the Mexican multifaceted rural-development program Sembrando Vida (SV) to the SDGs, to assess its policy coherence for sustainable development, especially in relation to climate change. We reviewed online documents and newspaper articles, interviewed key SV staff and analyzed the Mexican President’s morning conference speeches. We show that multiplicity and adaptation of stated intentions suggest opportunistic forms of policy drift with limited policy coherence. The potential of the SV program remains promising, but it requires clearer objectives, coherent strategy, expert knowledge, community support and evaluation. These results demonstrate how political context can cause policy drift and negatively impact intended policy coherence for sustainable development.Peer reviewe
Excuse Me I am Expanding : Butoh dance as an embodied method for experiencing and expressing ecological selfhoods
Get PDFThis project explores how embodied practice can generate and express experiences of ecological selfhood – the felt sense of being a porous entity which extends indefinitely beyond the skin. Through practice as research, Butoh dance (a twentieth century form originating in Japan) is adapted to interrogate the possibilities for a dancer to intentionally expand their selfhood, and to express this experience directly to others through non-representational performance. The wider contexts are the Anthropocene and the dominant neoliberal capitalist view of selfhood as properly being individualist, skin-bound, and competitive. This research outlines how such individualism is implicated in driving ecological crisis through aggregate behavioural effects, underscoring the need for alternative understandings of selfhood. The project is situated within the fields of Butoh studies, ecological performance, ecological performance discourse, and ecosomatics.
The psychosomatic techniques necessary to expand selfhood are researched through studio practice and documented through journalling. An accessible audio guide is also presented to introduce the newcomer to such work. The use of these techniques as the basis for performance works is explored through a documented stage performance from the Edinburgh Festival Fringe and two dance films shot in Japan, Italy, Ireland, and Scotland. The resulting contribution, Playing with the Cut, is a method of altering the boundary between self and not-self through dance; a radial selfhood which expands and contracts contextually. The method is shown to facilitate experiences of ecological selfhood on the part of the dancer, and the generation of performance material for general audiences in which Playing with the Cut is at the core of the creation process. This project presents a distinctive contribution to reconfiguring selfhood as an essential component of humanity’s response to ecological and climate crisis
The growing methodological toolkit for identifying and studying social learning and culture in non-human animals
Get PDFFunding: Biotechnology and Biological Sciences Research Council (grant number BB/S018484/1); Gordon and Betty Moore Foundation (grant number GBMF9881); National Geographic Society (grant number NGS-82515R-20).There is a growing consensus that animals’ socially transmitted knowledge should be recognized when planning conservation management, but demonstrating social learning or culture can present considerable challenges, especially in the wild. Fortunately, decades of research have spawned a rich methodological toolkit for exactly this purpose. Here, we review principal approaches, including: social learning experiments; analyses of natural or experimentally seeded diffusions of novel behaviours, sometimes using specialist statistical techniques; mapping of behavioural variation across neighbouring, sympatric or captive groups, or at larger scales; and assessment of aspects of cross-generational transmission, including teaching, learning during ontogenetic development and cumulative change. Some methods reviewed were developed for captive studies, but have subsequently been adapted for application in the wild, or are useful for exploring a species’ general propensity to learn and transmit information socially. We highlight several emerging ‘rapid assessment’ approaches—including camera trapping, passive acoustic monitoring, animal-borne tags, AI-assisted data mining and computer simulations—that should prove useful in addressing particularly urgent conservation needs. We conclude by considering how best to use this growing methodological toolkit in practice, to guide further research on animal social learning and cultures, and maximize conservation and policy impact.Peer reviewe
A gymnasion assemblage lost at sea? : The statues from the Antikythera shipwreck reconsidered
Get PDFThe Antikythera shipwreck provides a rare chronological anchor in the history of Greek sculpture. The cargo, a massive haul of more than four-dozen bronze and marble statues, in addition to amphorae and portable luxury goods, was lost at sea c. 70–50 BCE, possibly later, along the north-east coast of the island of Antikythera. Previous research on the sculptural assemblage from the wreck has focused on the style and iconographic heritage of individual statues. This article examines the statuary as a gathered whole to isolate trends in material, size, and subject matter. The results suggest a main setting where some, maybe all, of the statues might have originally been displayed: the gymnasion. The statues were probably obtained through plunder or extortion, not normal commercial activity. The study concludes by considering where the statues might have been set up once they reached their presumed destination in Italy. It is shown that the statues were most appropriate for display in a lavish public building in Rome.Peer reviewe
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