arXiv subjects

Helen Meskhidze

Publications and source records attributed to Helen Meskhidze.

8 recordsLinked to original sources

arXiv2026

Governed Collaborative Memory as Artificial Selection in LLM-Based Multi-Agent Systems

Persistent memory is turning language-model-based agents from stateless participants in isolated interactions into state-bearing components of LLM-based multi-agent systems. As memory becomes durable, reloadable, and behavior-shaping across agents, sessions, or versions, a design question arises that is not captured by retrieval accuracy or access control alone: which candidate memories should become shared institutional state? This Viewpoint frames that problem as governed collaborative memory. We argue that memory governance functions as a selection regime, determining which memory variants persist, which remain private, and which are rejected, abstained from, or superseded. We distinguish ungoverned persistence, constitutional or hybrid selection, automatic metric-based selection, and human-ratified artificial selection, emphasizing that these regimes are not a ranking but a design choice over target properties. We then describe a layered architecture that separates agent-local memory, shared institutional memory, archive memory, and project-continuity memory, with provenance and version lineage making selection inspectable. Documented traces from one running LLM-based multi-agent ecosystem illustrate unmanaged false-memory persistence, ratified institutional memory, rejection and revision, identity-preserving expansion, and governance-as-learning. The contribution is a design agenda: persistent LLM-based multi-agent systems should evaluate memory not only for recall and performance, but also for provenance fidelity, selection traceability, epistemic quality, correction pathways, and role preservation.

cs.MA↗

arXiv2024

The Classical Limit of Teleparallel Gravity

I consider the classical (i.e., non-relativistic) limit of Teleparallel Gravity, a relativistic theory of gravity that is empirically equivalent to General Relativity and features torsional forces. I show that as the speed of light is allowed to become infinite, Teleparallel Gravity reduces to Newtonian Gravity without torsion. I compare these results to the torsion-free context and discuss their implications on the purported underdetermination between Teleparallel Gravity and General Relativity. I conclude by considering alternative approaches to the classical limit developed in the literature.

physics.hist-ph↗

arXiv2024

Are General Relativity and Teleparallel Gravity Theoretically Equivalent?

Teleparallel gravity shares many qualitative features with general relativity, but differs from it in the following way: whereas in general relativity, gravitation is a manifestation of space-time curvature, in teleparallel gravity, spacetime is (always) flat. Gravitational effects in this theory arise due to spacetime torsion. It is often claimed that teleparallel gravity is an equivalent reformulation of general relativity. In this paper we question that view. We argue that the theories are not equivalent, by the criterion of categorical equivalence and any stronger criterion, and that teleparallel gravity posits strictly more structure than general relativity.

physics.hist-ph↗

arXiv2023

Torsion in the Classical Spacetime Context

Teleparallel gravity, an empirically equivalent counterpart to General Relativity, represents the influence of gravity using torsional forces. It raises questions about theory interpretation and underdetermination. To better understand the torsional forces of Teleparallel gravity, we consider a context in which forces are better understood: classical spacetimes. We propose a method of incorporating torsion into the classical spacetime context that yields a classical theory of gravity with a closed temporal metric and spacetime torsion. We then prove a result analogous to the Trautman degeometrization theorem, that every model of Newton-Cartan theory gives rise, non-uniquely, to a model of this theory.

physics.hist-ph↗

arXiv2022

Comparing Implementations of Self-Interacting Dark Matter in the Gizmo and Arepo Codes

Self-interacting dark matter (SIDM) models have received great attention over the past decade as solutions to the small-scale puzzles of astrophysics. Though there are different implementations of dark matter (DM) self-interactions in N-body codes of structure formation, there has not been a systematic study to compare the predictions of these different implementations. We investigate the implementation of dark matter self-interactions in two simulation codes: Gizmo and Arepo. We begin with identical initial conditions for an isolated $10^{10}$ M$_\odot$ dark matter halo and investigate the evolution of the density and velocity dispersion profiles in Gizmo and Arepo for SIDM cross-section over mass of 1, 5, and 50 $\rm cm^2 g^{-1}$. Our tests are restricted to the core expansion phase where the core density decreases and core radius increases with time. We find better than 30% agreement between the codes for the density profile in this phase of evolution, with the agreement improving at higher resolution. We find that varying code-specific SIDM parameters changes the central halo density by less than 10% outside of the convergence radius. We argue that SIDM core formation is robust across the two different schemes and conclude that these codes can reliably differentiate between cross-sections of 1, 5, and 50 $\rm cm^2 g^{-1}$ but finer distinctions would require further investigation.

astro-ph.GA↗

arXiv2017

Near-Infrared Stellar Populations in the metal-poor, Dwarf irregular Galaxies Sextans A and Leo A

We present JHK$_{s}$ observations of the metal-poor ([Fe/H] $<$ -1.40) Dwarf-irregular galaxies, Leo A and Sextans A obtained with the WIYN High-Resolution Infrared Camera at Kitt Peak. Their near-IR stellar populations are characterized by using a combination of colour-magnitude diagrams and by identifying long-period variable stars. We detected red giant and asymptotic giant branch stars, consistent with membership of the galaxy's intermediate-age populations (2-8 Gyr old). Matching our data to broadband optical and mid-IR photometry we determine luminosities, temperatures and dust-production rates (DPR) for each star. We identify 32 stars in Leo A and 101 stars in Sextans A with a DPR $>10^{-11}$ $M_\odot \,{\rm yr}^{-1}$, confirming that metal-poor stars can form substantial amounts of dust. We also find tentative evidence for oxygen-rich dust formation at low metallicity, contradicting previous models that suggest oxygen-rich dust production is inhibited in metal-poor environments. The total rates of dust injection into the interstellar medium of Leo A and Sextans A are (8.2 $\pm$ 1.8) $\times 10^{-9}$ $M_\odot \,{\rm yr}^{-1}$ and (6.2 $\pm$ 0.2) $\times 10^{-7}$ $M_\odot \,{\rm yr}^{-1}$, respectively. The majority of this dust is produced by a few very dusty evolved stars, and does not vary strongly with metallicity.

astro-ph.GA↗

arXiv2017

An Atlas of Star-Forming Galaxy Equivalent Widths

We present an atlas of starburst galaxy emission lines spanning 10 orders of magnitude in ionizing flux and 7 orders of magnitude in hydrogen number density. Coupling SEDs from Starburst99 with photoionization calculations from Cloudy, we track 96 emission lines from 977 Å to 205 m which are common to nebular regions, have been observed in H II regions, and serve as useful diagnostic lines. Each simulation grid displays equivalent widths and contains ~1.5x10$^4$ photoionization models calculated by supplying a spectral energy distribution, chemical abundances, dust content, and gas metallicity (ranging from 0.2 Z$\odot$ to 5.0 Z$\odot$). Our simulations will prove useful in starburst emission line data analysis, especially regarding local starburst galaxies that show high ionization emission lines. One sample application of our atlas predicts that C IV $λ$1549 will serve as a useful diagnostic emission line of vigorous star formation for coming James Webb Space Telescope observations predicting a peak equivalent width of approximately 316 Å.

astro-ph.GA↗

arXiv2016

Interpreting the Ionization Sequence in Star-Forming Galaxy Emission-Line Spectra

High ionization star forming (SF) galaxies are easily identified with strong emission line techniques such as the BPT diagram, and form an obvious ionization sequence on such diagrams. We use a locally optimally emitting cloud model to fit emission line ratios that constrain the excitation mechanism, spectral energy distribution, abundances and physical conditions along the star-formation ionization sequence. Our analysis takes advantage of the identification of a sample of pure star-forming galaxies, to define the ionization sequence, via mean field independent component analysis. Previous work has suggested that the major parameter controlling the ionization level in SF galaxies is the metallicity. Here we show that the observed SF- sequence could alternatively be interpreted primarily as a sequence in the distribution of the ionizing flux incident on gas spread throughout a galaxy. Metallicity variations remain necessary to model the SF-sequence, however, our best models indicate that galaxies with the highest and lowest observed ionization levels (outside the range -0.37 < log [O III]/H\b{eta} < -0.09) require the variation of an additional physical parameter other than metallicity, which we determine to be the distribution of ionizing flux in the galaxy.

astro-ph.GA↗