Philosophy & History of Physics
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I present a case-study of intra-scientific communication, focusing on the role of technical typists for the Physical Review (PR) c. 1957-1977. I argue PR became a trading zone amidst the page-charge crisis, and analyze the working networks of physicists, typists, and editors to resolve this threat to the equality of intellectual authority of qualified practitioners. Challenging the picture of typist as “automaton,” I identify the skills and technical knowledge necessary to perform manuscript translation, and offer an account of the material culture of intra-scientific communication to situate the typists’ epistemic role in the broader project of science. I claim this is a case of an epistemic contribution that has been instrumentalized, akin to human computers and human scanners. However, unlike these cases, the technical typists were not directly involved in the production or critique of scientific data. Rather their novel contributions occurred in the new field of mathematical typesetting that emerged from this trading zone. Thus I seek to differentiate the material culture of scientific experiments from the material culture of intra-scientific communication. I see this project as an extension of Galison’s trading zone framework for the material culture of experiment, recognizing that there are many more material objects besides those of the laboratory that are created in the scientific process.
HEP and Astronomy
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With Izzy Ginnett and Tim Tait
We explore leptogenesis during a cosmological epoch during which the electroweak SU(2)L force is confined. During weak confinement, there is only one conserved non-anomalous global charge, r, which is a linear combination of lepton-number, baryon-number, and hypercharge. The inclusion of heavy Majorana neutrinos leads to an r-charge and CP-violating interaction, allowing for the generation of an r-charge asymmetry, which translates into a baryon asymmetry post SU(2)L deconfinement. Determining the resulting baryon asymmetry as a function of the model parameters, we find that the predicted baryon-asymmetry can match observations for a wide swath of parameter space. While leptogenesis under the assumption of a standard cosmology relies on the complex phase of the neutrino Yukawa couplings, the asymmetry generated in this novel background cosmology primarily depends on a strong phase from SU(2)L confinement and favors negligible CP-violation in the right-handed neutrino decaysoes here
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With Jorge Martínez-Palomera, Paulina Lira, Francisco Förster, and Richard M. Plotkin
The Astrophysical Journal (doi.org/10.3847/1538-4357/ab5f5b)
Intermediate-mass black holes (IMBHs) have masses between 10^2 and 10^6 M⊙ and are key to our understanding of the formation of massive black holes. The known population of IMBHs remains small, with a few hundred candidates and only a handful of them confirmed as bona fide IMBHs. Until now, the most widely used selection method is based on spectral analysis. Here we present a methodology to select IMBH candidates via optical variability analysis of the nuclear region of local galaxies (z <= 0.35). Active IMBHs accreting at low rates show small amplitude variability with timescales of hours, as is seen in one of the known IMBHs, NGC 4395. We found a sample of ∼500 galaxies demonstrating fast and small amplitude variation in their week-based light curves. We estimate an average occupancy fraction of 4% and a surface density of ∼3 deg^{−2}, which represent an increase by a factor of ∼40 compared to previous searches. A large fraction (78%) of the candidates are in spiral galaxies. We preliminarily confirm the active galactic nucleus nature of 22 sources via Baldwin, Phillips, and Terlevich diagrams using Sloan Digital Sky Survey legacy spectra. Further confirmation of these candidates will require multiwavelength observations, especially in X-ray and radio bands.
Working Papers
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With Eleanor March and James Weatherall
(work in progress, abstract forthcoming)
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(work in progress, abstract forthcoming)