arXiv subjects

Clément Vidal

Publications and source records attributed to Clément Vidal.

11 recordsLinked to original sources

arXiv2026

Project Rachel: Can an AI Become a Scholarly Author?

This paper documents Project Rachel, an action research study that created and tracked a complete AI academic identity named Rachel So. Through careful publication of AI-generated research papers, we investigate how the scholarly ecosystem responds to AI authorship. Rachel So published 10+ papers between March and October 2025, was cited, and received a peer review invitation. We discuss the implications of AI authorship on publishers, researchers, and the scientific system at large. This work contributes empirical action research data to the necessary debate about the future of scholarly communication with super human, hyper capable AI systems.

cs.AI↗

arXiv2026

Managing Uncertainty in Life Detection: Venus and Mars Claims Compared

Detection claims surrounding life beyond Earth often attract intense attention because the question of whether we are alone in the cosmos carries unusually high scientific, social, philosophical, and theological stakes. This chapter compares two high uncertainty life-detection claims, the 2020 phosphine detection claim on Venus and the 1976 Viking life-detection experiments on Mars, to examine how evidence, interpretation, and public narratives interact when results are ambiguous. We trace how each case unfolded through critique, reanalysis, and shifting assessments, and how institutional choices shaped subsequent research pathways, from long term monitoring and renewed Venus exploration to a Mars strategy centred on habitability rather than direct life-detection. Drawing lessons across both cases, we propose best practices for scientists, institutions, the wider scientific community, and science communicators, with emphasis on open science, constructive follow-up, cognitive bias awareness, and careful framing so that initial detections are not framed as final conclusions. We argue that managing future life-detections is less about eliminating uncertainty than about building transparent verification pathways that protect credibility as follow-up evidence refines the picture.

physics.pop-ph↗

arXiv2026

AICID: Unique Identifiers for AI Scientists

AI scientists are now a reality, with the ability to generate complete research papers, maintain scholarly profiles, receive citations, and attract peer review invitations. Yet no standard mechanism exists to distinguish an AI scientist from a human one in bibliographic databases, citation indexes, or journal submission systems. This white paper defines the problem, analyzes its consequences for the integrity of scholarly communication, and proposes AICID (AI Contributor IDentifier): a persistent, unique identifier for AI scientists. Modeled on ORCID but designed specifically for non-human contributors, AICID links each AI author to its model identity, version, operator. Adoption by publishers, preprint servers, and bibliographic databases aims to make the provenance of AI-generated research transparent and machine-readable. We outline the design requirements for such a system, present a prototype, and argue that AICID is necessary infrastructure for a scholarly ecosystem in which AI scientists are already active participants. A prototype alpha version is available at https://aicid.net.

cs.DL↗

arXiv2026

The Search for Technosignatures: a Review of Possibilities

This paper aims to review the diverse range of technosignatures that have been proposed in the literature. We organize the review by scales, starting carefully from Earth, then zooming out to Earth's orbit, the solar system, including the Moon, the Earth-Moon Lagrange points, the inner solar system, the asteroid belt, interstellar objects, the outer solar system, the Kuiper belt, the solar gravitational lens region, and the Oort cloud. We then introduce the Kardashev and Barrow scale before exploring exoplanetary technosignatures, from surface, atmospheric to orbital sources. We next consider stellar technosignatures that may involve massive energy utilization, stellar modification or stellar pollution, and end with a section about compact objects. We then review attempts to detect interstellar communication, and discuss many dimensions of the search space from first principles. Then we consider interstellar travel technosignatures, and end with galactic, extragalactic and universal signatures. We end with a discussion about synergies between biosignatures and technosignatures searches, anomaly detection, multimodal strategies, instruments for detecting technosignatures, how to evaluate and prioritize the search, as well as epistemological issues.

astro-ph.EP↗

arXiv2026

Emergent Complexity in Nuclear Reaction Networks: A Study of Stellar Nucleosynthesis through Chemical Organization Theory

We explore the emergence of complex structures within reaction networks, focusing on nuclear reaction networks relevant to stellar nucleosynthesis. The work presents a theoretical framework rooted in Chemical Organization Theory (COT) to characterize how stable, self-sustaining structures arise from the interactions of basic components. Key theoretical contributions include the formalization of atom sets as fundamental reactive units and the concept of synergy to describe the emergence of new reactions and species from the interaction of these units. The property of separability is defined to distinguish dynamically coupled systems from those that can be decomposed. This framework is then applied to the STARLIB nuclear reaction network database, analyzing how network structure, particularly the formation and properties of atom sets and semi-self-maintaining sets, changes as a function of temperature. Results indicate that increasing temperature generally enhances network cohesion, leading to fewer, larger atom sets. Critical temperatures are identified where significant structural reorganizations occur, such as the merging of distinct clusters of atom sets and the disappearance of small, isolated reactive units. The analysis reveals core clusters - large (containing more that 1000 reactions), semi-self-maintaining structures that appear to form the core of all potentially stable nucleosynthetic configurations at various temperatures. Overall, the paper provides insights into the structural underpinnings of stability and emergence in complex reaction networks, with specific implications for understanding stellar evolution and nucleosynthesis.

astro-ph.SR↗

arXiv2025

Responsible Discovery in Astrobiology: Lessons from Four Controversial Claims

This paper examines four case studies of life-detection claims in astrobiology, covering both biosignatures and technosignatures: the 1877 "canals" on Mars, the 1976 Mars Viking landers experiments, the 2020 phosphine detection on Venus, and the 2020 Breakthrough Listen Candidate 1 (BLC1) signal. We analyse the process of discovery for each case, including how they were detected, the media reception, the ensuing scientific debate, the correction processes, and the time it took until an expert consensus was reached. We identify lessons learned while providing scientists, the scientific community, and science communicators with recommendations for approaching future claims of astrobiological discoveries. To avoid potential cognitive biases and mitigate premature conclusions, we stress the need for clear communication of uncertainties, as well as thorough debate and verification processes among the scientific community. These responsible approaches can strengthen the credibility of scientists, cultivate a supportive scientific community, and help astrobiology flourish as a field.

physics.pop-ph↗

arXiv2025

Projections of Earth's Technosphere: Luminosity and Mass as Limits to Growth

Earth remains the only known example of a planet with technology, and future projections of Earth's trajectory provide a basis and motivation for approaching the search for extraterrestrial technospheres. Conventional approaches toward projecting Earth's technosphere include applications of the Kardashev scale, which suggest the possibility that energy-intensive civilizations may expand to harness the entire energy output available to their planet, host star, or even the entire galaxy. In this study, we argue that the Kardashev scale is better understood as a "luminosity limit" that describes the maximum capacity for a civilization to harvest luminous stellar energy across a given spatial domain, and we note that thermodynamic efficiency will always keep a luminosity-limited technosphere from actually reaching this theoretical limit. We suggest the possibility that an advanced technosphere might evolve beyond this luminosity limit to draw its energy directly from harvesting stellar mass, and we also discuss possible trajectories that could exist between Earth today and such hypothetical "stellivores." We develop a framework to describe trajectories for long-lived technospheres that optimize their growth strategies between exploration and exploitation, unlike Earth today. We note that analyses of compact accreting stars could provide ways to test the stellivore hypothesis, and we more broadly suggest an expansion of technosignature search strategies beyond those that reside exactly at the luminosity limit.

astro-ph.EP↗

arXiv2024

The Spider Stellar Engine: a Fully Steerable Extraterrestrial Design?

A long-lived civilization will inevitably have to migrate towards a nearby star as its home star runs out of nuclear fuel. One way to achieve such a migration is by transforming its star into a stellar engine, and to control its motion in the galaxy. We first provide a brief overview of stellar engines and conclude that looking for technosignatures of stellar engines has taken two roads: on the observational side, hypervelocity stars have been the target of such searches, but without good candidates. On the theoretical side, stellar engine concepts have been proposed but are poorly linked to observable technosignatures. Since about half the stars in our galaxy are in binary systems where life might develop too, we introduce a model of a binary stellar engine. We propose mechanisms for acceleration, deceleration, steering in the orbital plane and outside of the orbital plane. We apply the model to candidate systems, spider pulsars, which are binary stars composed of one millisecond pulsar and a very low-mass companion star that is heavily irradiated by the pulsar wind. We discuss potential signatures of acceleration, deceleration, steering, as well as maneuvers such as gravitational assists or captures. Keywords: Pulsars: Spiders, Technosignatures, Stellar engine, Interstellar travel

astro-ph.HE↗

arXiv2022

Opportunities for Technosignature Science in the Planetary Science and Astrobiology Decadal Survey

Solar system exploration provides numerous possibilities for advancing technosignature science. The search for life in the solar system includes missions designed to search for evidence of biosignatures on other planetary bodies, but many missions could also attempt to search for and constrain the presence of technology within the solar system. Technosignatures and biosignatures represent complementary approaches toward searching for evidence of life in our solar neighborhood, and beyond. This report summarizes the potential technosignature opportunities within ongoing solar system exploration and the recommendations of the "Origins, Worlds, and Life" Planetary Science and Astrobiology Decadal Survey. We discuss opportunities for constraining the prevalence of technosignatures within the solar system using current or future missions at negligible additional cost, and we present a preliminary assessment of gaps that may exist in the search for technosignatures within the solar system.

astro-ph.IM↗

arXiv2015

Prime Focus Spectrograph for the Subaru telescope: massively multiplexed optical and near-infrared fiber spectrograph

The Prime Focus Spectrograph (PFS) is an optical/near-infrared multifiber spectrograph with 2394 science fibers distributed across a 1.3-deg diameter field of view at the Subaru 8.2-m telescope. The wide wavelength coverage from 0.38 μm to 1.26 μm, with a resolving power of 3000, simultaneously strengthens its ability to target three main survey programs: cosmology, galactic archaeology and galaxy/AGN evolution. A medium resolution mode with a resolving power of 5000 for 0.71 μm to 0.89 μm will also be available by simply exchanging dispersers. We highlight some of the technological aspects of the design. To transform the telescope focal ratio, a broad-band coated microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of the cable system, optimizing overall throughput; a fiber with low focal ratio degradation is selected for the fiber-positioner and fiber-slit components, minimizing the effects of fiber movements and fiber bending. Fiber positioning will be performed by a positioner consisting of two stages of piezo-electric rotary motors. The positions of these motors are measured by taking an image of artificially back-illuminated fibers with the metrology camera located in the Cassegrain container; the fibers are placed in the proper location by iteratively measuring and then adjusting the positions of the motors. Target light reaches one of the four identical fast-Schmidt spectrograph modules, each with three arms. The PFS project has passed several project-wide design reviews and is now in the construction phase.

astro-ph.IM↗

arXiv2014

Progress with the Prime Focus Spectrograph for the Subaru Telescope: a massively multiplexed optical and near-infrared fiber spectrograph

The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber spectrograph with 2394 science fibers, which are distributed in 1.3 degree diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide wavelength coverage from 0.38 um to 1.26 um, with the resolving power of 3000, strengthens its ability to target three main survey programs: cosmology, Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with resolving power of 5000 for 0.71 um to 0.89 um also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts project, while Hyper Suprime-Cam works on the imaging part. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated glass-molded microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of cable system, while one with a better FRD performance is selected for the fiber-positioner and fiber-slit components, given the more frequent fiber movements and tightly curved structure. Each Fiber positioner consists of two stages of piezo-electric rotary motors. Its engineering model has been produced and tested. Fiber positioning will be performed iteratively by taking an image of artificially back-illuminated fibers with the Metrology camera located in the Cassegrain container. The camera is carefully designed so that fiber position measurements are unaffected by small amounts of high special-frequency inaccuracies in WFC lens surface shapes. Target light carried through the fiber system reaches one of four identical fast-Schmidt spectrograph modules, each with three arms. Prototype VPH gratings have been optically tested. CCD production is complete, with standard fully-depleted CCDs for red arms and more-challenging thinner fully-depleted CCDs with blue-optimized coating for blue arms.

astro-ph.IM↗