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Jamee Elder

Publications and source records attributed to Jamee Elder.

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Black Boxes in Black Hole Imaging

We investigate the epistemic opacity of computer simulations and machine learning methods in the context of black hole imaging. We argue that there are forms of opacity-including opacity resulting from the use of machine learning-which do not need to affect the reliability of an inference when it is seen as a part of a broader inferential framework. We propose conditions under which that can plausibly be the case, and discuss how opaque methods can be useful in the context of the (next generation) Event Horizon Telescope. However, we also argue that at least one problematic form of opacity is currently present in black hole imaging: GRMHD models of Sagittarius A* are opaque. This form of opacity signals the limitations of current understanding of the models of this source, and constrains the potential uses of ML models in future observations.

physics.hist-ph

How Theory-laden are Observations of Black Holes?

We evaluate the roles general relativistic assumptions play in simulations used in recent observations of black holes including LIGO-Virgo and the Event Horizon Telescope. In both experiments simulations play an ampliative role, enabling the extraction of more information from the data than would be possible otherwise. This comes at a cost of theory-ladenness. We discuss the issue of inferential circularity, which arises in some applications; classify some of the epistemic strategies used to reduce the extent of theory-ladenness; and discuss ways in which these strategies are model independent.

physics.hist-ph

Robustness and the Event Horizon Telescope: the case of the first image of M87*

We examine the justification for taking the Event Horizon Telescope's famous 2019 image to be a reliable representation of the region surrounding a black hole. We argue that it takes the form of a robustness argument, with the resulting image being robust across variation in a range of data-analysis pipelines. We clarify the sense of "robustness" operating here and show how it can account for the reliability of astrophysical inferences, even in cases -- like the EHT -- where these inferences are based on experiments that are (for all practical purposes) unique. This has consequences far beyond the 2019 image.

physics.hist-ph

Key Science Goals for the Next-Generation Event Horizon Telescope

The Event Horizon Telescope (EHT) has led to the first images of a supermassive black hole, revealing the central compact objects in the elliptical galaxy M87 and the Milky Way. Proposed upgrades to this array through the next-generation EHT (ngEHT) program would sharply improve the angular resolution, dynamic range, and temporal coverage of the existing EHT observations. These improvements will uniquely enable a wealth of transformative new discoveries related to black hole science, extending from event-horizon-scale studies of strong gravity to studies of explosive transients to the cosmological growth and influence of supermassive black holes. Here, we present the key science goals for the ngEHT and their associated instrument requirements, both of which have been formulated through a multi-year international effort involving hundreds of scientists worldwide.

astro-ph.HE