arXiv subjects

Daniel Glazer

Publications and source records attributed to Daniel Glazer.

5 recordsLinked to original sources

arXiv2026

Cosmology, Cluster Algebras, and $\boldsymbol{u}$

We explore the cluster algebra structures present in the wavefunction and correlators of conformally coupled scalar fields in de Sitter space. To connect cosmological kinematics to cluster variables, we utilize the so-called $u$-variables that appear on both sides. Since $u$-variables parameterize a rigid space, it is natural to identify the ones that appear from cosmological graphs and those that arise from cluster algebras. This provides a mapping between kinematic variables and cluster variables. For $n$-site chain Feynman graphs, this gives a coordinate-invariant relation to $A_{2n-2}$-type cluster algebras, while in the case of $n$-site cycle graph momentum integrands, the relevant cluster algebra is $B_{2n-1}$, as found previously. Since kinematic variables are mapped to nonlinear combinations of cluster variables, cluster compatibility imposes strong conditions on possible symbol entries. We use this notion of compatibility to bootstrap the symbol. In the chain case, both the cosmological wavefunction and products of lower-point functions satisfy cluster compatibility, with the correlator a particular combination, so that the wavefunction and correlator share the same cluster structure. In the cycle case, however, the wavefunction appears to be uniquely selected by the cluster structure, and the correlator does not display the same compatibility as the wavefunction.

hep-th↗

arXiv2025

Picture an Astronomer: Best Practices for Retaining Talent in Astrophysics

Women are consistently underrepresented in astrophysics yet are simultaneously subject to disproportionate attrition at every career stage. This disparity between demonstrated efficacy in job performance and ultimate career outcome was the primary motivation for the Picture an Astronomer series, which included both targeted public outreach to increase representation of women in astrophysics and high-level, solution-oriented discussions among professional astronomers. In March 2025, more than 200 astronomers came together in a hybrid-format symposium focused on the state of the field for female scientists, combining scientific exchange with discussions of policies and practices to strengthen retention of talent in the field. This white paper is the result of those discussions, offering a wide range of recommendations developed in the context of gendered attrition in astrophysics but which ultimately support a healthier climate for all scientists alike.

astro-ph.IM↗

arXiv2025

Dynamical Tidal Response of Schwarzschild Black Holes

Dynamical Love numbers capture the conservative response of an object to a time-dependent external tidal gravitational field. We compute the dynamical Love numbers of Schwarzschild black holes in general relativity within a point-particle effective field theory framework. In addition to the known logarithmic running, we compute the finite scheme-dependent contributions to the Love number couplings. We do this by matching the renormalized one-point function in the effective theory to the classical field profile computed in general relativity. On the general relativity side, we solve the Regge-Wheeler and Zerilli equations perturbatively in a small frequency expansion. In order to match on the effective field theory side we include gravitational interactions using the Born series and employ dimensional regularization to obtain a renormalized field profile.

gr-qc↗

arXiv2024

Higher-Dimensional Black Holes and Effective Field Theory

We study the scalar tidal responses of spinning higher-dimensional black holes, and their effective field theory description. After constructing the effective field theory of a spinning point particle in general dimension, we apply this theory to match the scalar responses of a variety of black hole solutions. In addition to the five-dimensional Myers--Perry black hole, we derive the scalar responses of spinning black holes in the large $D$ limit, and also study the responses of black holes in the ultra-spinning regime. We find that in the most generic case, the static responses of higher-dimensional spinning black holes do not vanish, but for special cases we find a pattern of zeroes in the responses, similar to other known examples. Further, we observe various interesting relations between the responses.

hep-th↗

arXiv2018

The Reionization Parameter Space Consistent with the Thomson Optical Depth from Planck

We study the reionization parameter space consistent with the current measurement of the Thomson optical depth using a new parametrization of the reionization history. The mass-weighted ionization fraction is specified in terms of the redshift midpoint, duration, and asymmetry shape parameters. We perform an MCMC analysis using conservative flat priors and physical constraints. Our analysis yields a redshift midpoint of $z_{50}=7.66\substack{+0.57-0.61}\text{(68%)}\substack{+1.26-1.02}\text{(95%)}$, and upper limits on the duration $Δ_\text{z} < 7.5$ and asymmetry $A_\text{z}<5.3$ for $τ= 0.054 \pm 0.007$. The reconstructed mass-weighted ionization fraction $x_\text{i}(z)$ is asymmetric, but early contributions to reionization are minor.

astro-ph.CO↗