Pub Date : 2025-12-18DOI: 10.1007/s10701-025-00906-6
Niccolò Covoni, Vincenzo Fano, Marco Sanchioni
This paper examines the role of perspectivism in Relational Quantum Mechanics, situating it within the broader landscape of quantum interpretations and the scientific realism debate. We argue that, while interpretations such as QBism embrace strong forms of perspectivism, Relational Quantum Mechanics adopts a “soft” perspectivism, limiting the observer’s role to selecting experimental contexts without compromising its realist framework. We also explore the historical roots of Relational Quantum Mechanics, showing that relational ideas in the works of Bohr and other pioneers similarly avoided strong perspectivist commitments. By analyzing both contemporary and historical perspectives, we argue that Relational Quantum Mechanics offers a minimalist yet robust relational interpretation, distinct from more subjectivist approaches.
{"title":"Relational Quantum Mechanics and (Soft) Perspectivism","authors":"Niccolò Covoni, Vincenzo Fano, Marco Sanchioni","doi":"10.1007/s10701-025-00906-6","DOIUrl":"10.1007/s10701-025-00906-6","url":null,"abstract":"<div><p>This paper examines the role of perspectivism in Relational Quantum Mechanics, situating it within the broader landscape of quantum interpretations and the scientific realism debate. We argue that, while interpretations such as QBism embrace strong forms of perspectivism, Relational Quantum Mechanics adopts a “soft” perspectivism, limiting the observer’s role to selecting experimental contexts without compromising its realist framework. We also explore the historical roots of Relational Quantum Mechanics, showing that relational ideas in the works of Bohr and other pioneers similarly avoided strong perspectivist commitments. By analyzing both contemporary and historical perspectives, we argue that Relational Quantum Mechanics offers a minimalist yet robust relational interpretation, distinct from more subjectivist approaches.</p></div>","PeriodicalId":569,"journal":{"name":"Foundations of Physics","volume":"56 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10701-025-00906-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145778854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1007/s10509-025-04526-4
Richard Ignace, Christiana Erba, Kaylee DeGennaro, Gary D. Henson
Evolved late-type stars are frequently identified as photometric and spectroscopic variables, such as Mira-type or semi-regular variable objects. These stars can also be polarimetrically variable, an indicator of non-spherical geometry for spatially unresolved sources. Departures from symmetry can arise in a number of ways, such as the presence of a binary companion (e.g., multiple illumination sources for scattered light), brightness variations in the stellar atmosphere (e.g., large convective cells), or aspherical circumstellar envelopes (e.g., disks or aspherical stellar winds). Common polarigenic opacities for cool stars include Rayleigh scattering and dust scattering. The classic wavelength dependence of (lambda ^{-4}) for Rayleigh single scattering is generally straightforward; however, that signature can be confounded by interstellar polarization (ISP). We explore strategies for interpreting polarimetric observations when the interstellar polarization (ISP) cannot be removed. We introduce a “hybrid” spectrum that includes both Rayleigh polarization for a stellar contribution and the Serkowski Law for an interstellar contribution. We find the polarization spectral slope can be more shallow than expected from Rayleigh scattering alone. For stellar variability, shorter wavelengths give higher amplitude changes when Rayleigh scattering dominates the interstellar signal. Quite anomalous slopes can occur over limited wavelength intervals if the stellar and interstellar position angles differ by (90^{circ }). Results of the models are discussed in the context of photopolarimetry methods, and an application is considered in terms of variable polarization from the carbon star, R Scl.
{"title":"Modeling of Rayleigh scattering and interstellar polarization for evolved late-type stars","authors":"Richard Ignace, Christiana Erba, Kaylee DeGennaro, Gary D. Henson","doi":"10.1007/s10509-025-04526-4","DOIUrl":"10.1007/s10509-025-04526-4","url":null,"abstract":"<div><p>Evolved late-type stars are frequently identified as photometric and spectroscopic variables, such as Mira-type or semi-regular variable objects. These stars can also be polarimetrically variable, an indicator of non-spherical geometry for spatially unresolved sources. Departures from symmetry can arise in a number of ways, such as the presence of a binary companion (e.g., multiple illumination sources for scattered light), brightness variations in the stellar atmosphere (e.g., large convective cells), or aspherical circumstellar envelopes (e.g., disks or aspherical stellar winds). Common polarigenic opacities for cool stars include Rayleigh scattering and dust scattering. The classic wavelength dependence of <span>(lambda ^{-4})</span> for Rayleigh single scattering is generally straightforward; however, that signature can be confounded by interstellar polarization (ISP). We explore strategies for interpreting polarimetric observations when the interstellar polarization (ISP) cannot be removed. We introduce a “hybrid” spectrum that includes both Rayleigh polarization for a stellar contribution and the Serkowski Law for an interstellar contribution. We find the polarization spectral slope can be more shallow than expected from Rayleigh scattering alone. For stellar variability, shorter wavelengths give higher amplitude changes when Rayleigh scattering dominates the interstellar signal. Quite anomalous slopes can occur over limited wavelength intervals if the stellar and interstellar position angles differ by <span>(90^{circ })</span>. Results of the models are discussed in the context of photopolarimetry methods, and an application is considered in terms of variable polarization from the carbon star, R Scl.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"370 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145778974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.infrared.2025.106333
Hongyan Wang , Yangjing Zhao , Zongjie Sun , Shunchang Hu , Zheheng Jing , Xiaoke Li , Zengsheng Wang , Wuyi Ming
Infrared thermography is emerging as a non-invasive technique of significant importance in various industries due to its high efficiency, wide detection range. Furthermore, with the integration of deep learning techniques, the accuracy of industrial inspections has been significantly enhanced. This study categorizes the relevant literature into six major industries: renewable, civil, composite, machinery, metal, and other industries. These industries serve as distinct contexts for examining the applications of active and passive infrared imaging. Subsequently, the discussion revolves around the utilization of infrared thermography in conjunction with convolutional neural network, focusing on both the excitation sources and algorithms employed. A comparative analysis of the accuracy achieved with different excitation sources and algorithms is conducted. Furthermore, this investigation addresses the limitations and unresolved issues associated with the application of infrared thermography technology. It delves into the challenges faced in real-world scenarios and identifies areas where further research and development are warranted.
{"title":"The latest research of CNN in infrared industrial defect detection","authors":"Hongyan Wang , Yangjing Zhao , Zongjie Sun , Shunchang Hu , Zheheng Jing , Xiaoke Li , Zengsheng Wang , Wuyi Ming","doi":"10.1016/j.infrared.2025.106333","DOIUrl":"10.1016/j.infrared.2025.106333","url":null,"abstract":"<div><div>Infrared thermography is emerging as a non-invasive technique of significant importance in various industries due to its high efficiency, wide detection range. Furthermore, with the integration of deep learning techniques, the accuracy of industrial inspections has been significantly enhanced. This study categorizes the relevant literature into six major industries: renewable, civil, composite, machinery, metal, and other industries. These industries serve as distinct contexts for examining the applications of active and passive infrared imaging. Subsequently, the discussion revolves around the utilization of infrared thermography in conjunction with convolutional neural network, focusing on both the excitation sources and algorithms employed. A comparative analysis of the accuracy achieved with different excitation sources and algorithms is conducted. Furthermore, this investigation addresses the limitations and unresolved issues associated with the application of infrared thermography technology. It delves into the challenges faced in real-world scenarios and identifies areas where further research and development are warranted.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"153 ","pages":"Article 106333"},"PeriodicalIF":3.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1007/s00723-025-01824-6
Pralekh Dubey, Shashank Kumar, Chinmaya Singh, Jemish Naliyapara, Monish A. Poojar, K. B. Hari Krishnan, Anshul Poonia, Phani Peddibhotla
Continuous-wave optically detected magnetic resonance (CW-ODMR) measurements with nitrogen-vacancy (NV) spins in diamond are used for sensing DC magnetic fields from nearby magnetic targets. However, this technique suffers from ambiguities in the extraction of the magnetic field components when resonances due to different NV orientation classes overlap with each other. Here, we perform detailed experimental and theoretical studies of such effects on NV ensembles experiencing low to moderate bias magnetic fields. In particular, through symmetry considerations, we systematically examine the ODMR response of different NV orientation classes as a function of the orientation of the magnetic field vector. Our studies are of importance for performing a careful and detailed analysis of the ODMR spectra in order to infer the vector magnetic field information. Our results find application in the studies of magnetic samples that require a low applied bias field and can also be potentially adapted to defect spins in other solid-state systems.
{"title":"Magnetic Field Orientation Dependence of Continuous-Wave Optically Detected Magnetic Resonance with Nitrogen-Vacancy Ensembles","authors":"Pralekh Dubey, Shashank Kumar, Chinmaya Singh, Jemish Naliyapara, Monish A. Poojar, K. B. Hari Krishnan, Anshul Poonia, Phani Peddibhotla","doi":"10.1007/s00723-025-01824-6","DOIUrl":"10.1007/s00723-025-01824-6","url":null,"abstract":"<div><p>Continuous-wave optically detected magnetic resonance (CW-ODMR) measurements with nitrogen-vacancy (NV) spins in diamond are used for sensing DC magnetic fields from nearby magnetic targets. However, this technique suffers from ambiguities in the extraction of the magnetic field components when resonances due to different NV orientation classes overlap with each other. Here, we perform detailed experimental and theoretical studies of such effects on NV ensembles experiencing low to moderate bias magnetic fields. In particular, through symmetry considerations, we systematically examine the ODMR response of different NV orientation classes as a function of the orientation of the magnetic field vector. Our studies are of importance for performing a careful and detailed analysis of the ODMR spectra in order to infer the vector magnetic field information. Our results find application in the studies of magnetic samples that require a low applied bias field and can also be potentially adapted to defect spins in other solid-state systems.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"57 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145778601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.3103/S106833562560370X
A. V. Kornilova, V. G. Yakunin, A. P. Kanavin, V. Yu. Timoshenko
The spatial distribution of the electric field of a light wave in ensembles of silicon nanowires (SiNWs) coated with gold nanoparticles (AuNPs) is calculated. It is found that, compared to the case of nanowires without nanoparticles, the electric field of a light wave in a SiNW/AuNP composite structure significantly increases, which is explained by the combined contribution of the enhancement of the local electric fields due to Mie scattering on silicon nanowires and the fields of localized surface plasmons in gold nanoparticles. It is shown that the local field enhancement is nonmonotonic and strongly dependent on the excitation wavelength in the 600–800 nm range, which is due to the manifestation of spectral maxima of elastic scattering of the excitation light in the silicon nanowire array. Enhancement also depends on the type of nanoparticle size distribution (monodisperse or lognormal) and is maximal at a nanowire space filling factor of approximately 50%. The obtained results explain the experimental data on giant Raman scattering in SiNW/AuNP structures excited by 633 nm light and point to further opportunities for improving the parameters of semiconductor–metal structures for use in optical molecular sensing methods.
{"title":"Enhancement of Local Electric Fields of Optical Radiation in Ensembles of Silicon Nanowires with Gold Nanoparticles","authors":"A. V. Kornilova, V. G. Yakunin, A. P. Kanavin, V. Yu. Timoshenko","doi":"10.3103/S106833562560370X","DOIUrl":"10.3103/S106833562560370X","url":null,"abstract":"<p>The spatial distribution of the electric field of a light wave in ensembles of silicon nanowires (SiNWs) coated with gold nanoparticles (AuNPs) is calculated. It is found that, compared to the case of nanowires without nanoparticles, the electric field of a light wave in a SiNW/AuNP composite structure significantly increases, which is explained by the combined contribution of the enhancement of the local electric fields due to Mie scattering on silicon nanowires and the fields of localized surface plasmons in gold nanoparticles. It is shown that the local field enhancement is nonmonotonic and strongly dependent on the excitation wavelength in the 600–800 nm range, which is due to the manifestation of spectral maxima of elastic scattering of the excitation light in the silicon nanowire array. Enhancement also depends on the type of nanoparticle size distribution (monodisperse or lognormal) and is maximal at a nanowire space filling factor of approximately 50%. The obtained results explain the experimental data on giant Raman scattering in SiNW/AuNP structures excited by 633 nm light and point to further opportunities for improving the parameters of semiconductor–metal structures for use in optical molecular sensing methods.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"52 7","pages":"S726 - S734"},"PeriodicalIF":0.7,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145772085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.3103/S0027134925700997
Yu. I. Papkova, S. O. Papkov
The problem of the sound field of a point sound source placed in a nonideal marine waveguide is considered. The boundaries of the waveguide are assumed to be plane-parallel, and three layers are distinguished: a water layer with an inhomogeneous refractive component of the sound speed, a layer of liquid sediments, and an elastic bottom layer on a rigid base. At the top, the water layer adjoins a homogeneous air half-space. For the given waveguide model, analytical expressions for the impedance functions at the boundaries of the water layer are obtained for the first time, which makes it possible to construct the Green’s function of the vertical boundary-value problem. Moreover, exact values for the residues of the Green’s function are found, which allows for writing down an exact analytical representation for the acoustic pressure potential in the form of a sum of normal modes. It is shown that, in this model, the influence of the continuous spectrum (integrals along the branch cuts) is small even at short distances from the source. As the thickness of the elastic layer decreases, the discrete spectrum of the problem tends to the values for the classical waveguide; with sufficiently large thickness and attenuation, it resembles the discrete spectrum of the Pekeris elastic waveguide. Examples of numerical implementation for waveguide parameters typical for the Black Sea region are given.
{"title":"On the Modeling of Acoustic Fields in a Marine Waveguide with Refined Boundary Conditions at the Surface and Bottom","authors":"Yu. I. Papkova, S. O. Papkov","doi":"10.3103/S0027134925700997","DOIUrl":"10.3103/S0027134925700997","url":null,"abstract":"<p>The problem of the sound field of a point sound source placed in a nonideal marine waveguide is considered. The boundaries of the waveguide are assumed to be plane-parallel, and three layers are distinguished: a water layer with an inhomogeneous refractive component of the sound speed, a layer of liquid sediments, and an elastic bottom layer on a rigid base. At the top, the water layer adjoins a homogeneous air half-space. For the given waveguide model, analytical expressions for the impedance functions at the boundaries of the water layer are obtained for the first time, which makes it possible to construct the Green’s function of the vertical boundary-value problem. Moreover, exact values for the residues of the Green’s function are found, which allows for writing down an exact analytical representation for the acoustic pressure potential in the form of a sum of normal modes. It is shown that, in this model, the influence of the continuous spectrum (integrals along the branch cuts) is small even at short distances from the source. As the thickness of the elastic layer decreases, the discrete spectrum of the problem tends to the values for the classical waveguide; with sufficiently large thickness and attenuation, it resembles the discrete spectrum of the Pekeris elastic waveguide. Examples of numerical implementation for waveguide parameters typical for the Black Sea region are given.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 5","pages":"898 - 907"},"PeriodicalIF":0.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145772151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.3103/S0027134925701024
P. N. Nikolaev
In this work, the main characteristics of the crystal–homogeneous phase transition in argon are calculated on the basis of the correlation cell-cluster expansion. Along the crystallization and melting line, the heat capacity at constant pressure is calculated for the crystalline phase and for the homogeneous phase. A monotonic decrease of the heat capacity at constant pressure with increasing temperature is observed. A comparison between theoretical data and experimental results is carried out, showing good agreement.
{"title":"Heat Capacity at Constant Pressure along the Crystallization and Melting Line of Argon","authors":"P. N. Nikolaev","doi":"10.3103/S0027134925701024","DOIUrl":"10.3103/S0027134925701024","url":null,"abstract":"<p>In this work, the main characteristics of the crystal–homogeneous phase transition in argon are calculated on the basis of the correlation cell-cluster expansion. Along the crystallization and melting line, the heat capacity at constant pressure is calculated for the crystalline phase and for the homogeneous phase. A monotonic decrease of the heat capacity at constant pressure with increasing temperature is observed. A comparison between theoretical data and experimental results is carried out, showing good agreement.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 5","pages":"875 - 880"},"PeriodicalIF":0.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145772264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.3103/S1068335625603024
P. V. Kazakevich, S. I. Yares’ko
We report experimental data on the UV, visible, and near-IR absorption spectra of a colloid obtained by pulsed laser ablation of gold with Nd:YAG laser radiation in a tetrahydrofuran medium. Data are presented on the dynamics of changes in colloid absorption upon irradiation with unfocused 266 nm radiation, resulting in the formation of a new absorption band peaking at 312 nm.
{"title":"UV Spectral Characteristics of a Gold Nanoparticle Colloid Obtained by Pulsed Laser Ablation in Tetrahydrofuran","authors":"P. V. Kazakevich, S. I. Yares’ko","doi":"10.3103/S1068335625603024","DOIUrl":"10.3103/S1068335625603024","url":null,"abstract":"<p>We report experimental data on the UV, visible, and near-IR absorption spectra of a colloid obtained by pulsed laser ablation of gold with Nd:YAG laser radiation in a tetrahydrofuran medium. Data are presented on the dynamics of changes in colloid absorption upon irradiation with unfocused 266 nm radiation, resulting in the formation of a new absorption band peaking at 312 nm.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"52 6","pages":"S630 - S635"},"PeriodicalIF":0.7,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145766297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1051/0004-6361/202558117
A. García Muñoz, D. De Fazio, D. J. Wilson, K. France
Context. Neptune-sized exoplanets (i.e., exo-Neptunes) are fundamental to the study of exoplanet diversity. Their evolution is sculpted by atmospheric escape, often traced by absorption in the H I Lyman-α line at 1216 Å and the He I triplet line at 1.08 μm. On the warm exo-Neptunes HAT-P-11 b, GJ 3470 b and GJ 436 b, H I Lyman-α absorption causes extreme in-transit obscuration of their host stars. This suggests that the He I triplet line absorption would be strong as well, yet it has only been identified on two of these planets.Aims. We explore processes that had previously been omitted, which might act to attenuate the He I triplet line on warm exo-Neptunes. In particular, we assess the role of vibrationally excited H2 to remove the He+ ion that acts as precursor of the absorbing He(23S).Methods. We determined thermal rate coefficients for this chemical process, leveraging the available theoretical and experimental data. The process becomes notably fast at the temperatures expected in the atmospheric layers probed by the He I triplet line.Results. Our simulations show that this removal process severely mutes the line on GJ 3470 b and leads to the nondetection on GJ 436 b. The overall efficiency of this mechanism is connected to the location in the atmosphere of the H2-to-H transition and, ultimately, to the amount of high-energy radiation received by the planet. The process will be more significant on small exoplanets than on hotter or more massive ones since, in the latter case, the H2-to-H transition generally occurs deeper in the atmosphere.Conclusions. Weak He I triplet line absorption does not necessarily imply the lack of a primordial, H2-He-dominated atmosphere, an idea to bear in mind when interpreting observations of other small exoplanets.
{"title":"Vibrationally excited H2 muting the He I triplet line at 1.08 μm on warm exo-Neptunes","authors":"A. García Muñoz, D. De Fazio, D. J. Wilson, K. France","doi":"10.1051/0004-6361/202558117","DOIUrl":"https://doi.org/10.1051/0004-6361/202558117","url":null,"abstract":"<i>Context.<i/> Neptune-sized exoplanets (i.e., exo-Neptunes) are fundamental to the study of exoplanet diversity. Their evolution is sculpted by atmospheric escape, often traced by absorption in the H I Lyman-<i>α<i/> line at 1216 Å and the He I triplet line at 1.08 μm. On the warm exo-Neptunes HAT-P-11 b, GJ 3470 b and GJ 436 b, H I Lyman-<i>α<i/> absorption causes extreme in-transit obscuration of their host stars. This suggests that the He I triplet line absorption would be strong as well, yet it has only been identified on two of these planets.<i>Aims.<i/> We explore processes that had previously been omitted, which might act to attenuate the He I triplet line on warm exo-Neptunes. In particular, we assess the role of vibrationally excited H<sub>2<sub/> to remove the He<sup>+<sup/> ion that acts as precursor of the absorbing He(2<sup>3<sup/><i>S<i/>).<i>Methods.<i/> We determined thermal rate coefficients for this chemical process, leveraging the available theoretical and experimental data. The process becomes notably fast at the temperatures expected in the atmospheric layers probed by the He I triplet line.<i>Results.<i/> Our simulations show that this removal process severely mutes the line on GJ 3470 b and leads to the nondetection on GJ 436 b. The overall efficiency of this mechanism is connected to the location in the atmosphere of the H<sub>2<sub/>-to-H transition and, ultimately, to the amount of high-energy radiation received by the planet. The process will be more significant on small exoplanets than on hotter or more massive ones since, in the latter case, the H<sub>2<sub/>-to-H transition generally occurs deeper in the atmosphere.<i>Conclusions.<i/> Weak He I triplet line absorption does not necessarily imply the lack of a primordial, H<sub>2<sub/>-He-dominated atmosphere, an idea to bear in mind when interpreting observations of other small exoplanets.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"2 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1051/0004-6361/202555791
Adrienn Pataki, Péter Raffai, István Csabai, Gábor Rácz, István Szapudi
We constrain AvERA cosmologies in comparison with the flat Λ-cold dark matter (ΛCDM) model using cosmic chronometer (CC) data and the Pantheon+ sample of type Ia supernovae (SNe Ia). The analysis includes fits to both CC and SN datasets using the dynesty dynamic nested sampling algorithm. For the model comparison, we used the Bayesian model evidence and Anderson-Darling tests applied to the normalized residuals to assess consistency with a standard normal distribution. Best-fit parameters were derived within the redshift ranges z ≤ 2 for CCs and z ≤ 2.3 for SNe. For the baseline AvERA cosmology, we obtained best-fit values of the Hubble constant of from the CC analysis and from the SN analysis, each consistent within 1σ with the corresponding AvERA simulation value of H(z = 0). While both the CC and SN datasets yield higher Bayesian evidence for the flat ΛCDM model, they favor the AvERA cosmologies according to the Anderson-Darling test. We have identified signs of overfitting in each model, which suggests the possibility of overestimating the uncertainties in the Pantheon+ covariance matrix.
{"title":"Constraints on AvERA cosmologies from cosmic chronometers and type Ia supernovae","authors":"Adrienn Pataki, Péter Raffai, István Csabai, Gábor Rácz, István Szapudi","doi":"10.1051/0004-6361/202555791","DOIUrl":"https://doi.org/10.1051/0004-6361/202555791","url":null,"abstract":"We constrain AvERA cosmologies in comparison with the flat Λ-cold dark matter (ΛCDM) model using cosmic chronometer (CC) data and the Pantheon+ sample of type Ia supernovae (SNe Ia). The analysis includes fits to both CC and SN datasets using the dynesty dynamic nested sampling algorithm. For the model comparison, we used the Bayesian model evidence and Anderson-Darling tests applied to the normalized residuals to assess consistency with a standard normal distribution. Best-fit parameters were derived within the redshift ranges <i>z<i/> ≤ 2 for CCs and <i>z<i/> ≤ 2.3 for SNe. For the baseline AvERA cosmology, we obtained best-fit values of the Hubble constant of from the CC analysis and from the SN analysis, each consistent within 1<i>σ<i/> with the corresponding AvERA simulation value of <i>H<i/>(<i>z<i/> = 0). While both the CC and SN datasets yield higher Bayesian evidence for the flat ΛCDM model, they favor the AvERA cosmologies according to the Anderson-Darling test. We have identified signs of overfitting in each model, which suggests the possibility of overestimating the uncertainties in the Pantheon+ covariance matrix.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"83 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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