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Full-Text Articles in Physics
Novel Integrated Sachs-Wolfe Effect From Early Dark Energy, Tristan L. Smith, J. T. Giblin Jr., M. Amin, M. Gerhardinger, E. Florio, M. Cerep, S. Daniels
Novel Integrated Sachs-Wolfe Effect From Early Dark Energy, Tristan L. Smith, J. T. Giblin Jr., M. Amin, M. Gerhardinger, E. Florio, M. Cerep, S. Daniels
Physics & Astronomy Faculty Works
We study the nonlinear effects of minimally coupled, massless, cosmological scalar fields on the cosmic microwave background (CMB). These fields can exhibit postrecombination parametric resonance and subsequent nonlinear evolution leading to novel contributions to the gravitational potential. We compute the resulting contributions to the CMB temperature anisotropies through the time variation of the gravitational potential (i.e., the integrated Sachs-Wolfe (ISW) effect). We find that fields that constitute 5% of the total energy density and become dynamical at zc ≃ 104 can produce marginally observable ISW signals at multipoles ℓ ≃ 2000. Fields that become dynamical at earlier times …
Comparative Analysis Of Interacting Stepped Dark Radiation, N. Schöneberg, G. F. Abellán, T. Simon, A. Bartlett, Y. Patel, Tristan L. Smith
Comparative Analysis Of Interacting Stepped Dark Radiation, N. Schöneberg, G. F. Abellán, T. Simon, A. Bartlett, Y. Patel, Tristan L. Smith
Physics & Astronomy Faculty Works
Models that address both the Hubble and S8 tensions with the same mechanism generically cause a prerecombination suppression of the small scale matter power spectrum. Here we focus on two such models. Both models introduce a self-interacting dark radiation fluid scattering with dark matter, which has a step in its abundance around some transition redshift. In one model, the interaction is weak and with all of the dark matter whereas in the other it is strong but with only a fraction of the dark matter. The weakly interacting case is able to address both tensions simultaneously and provide a …
Separated Twins Or Just Siblings? A Multiplanet System Around An M Dwarf Including A Cool Sub-Neptune, M. Harris, D. Dragomir, I. Mireles, K. A. Collins, S. Ulmer-Moll, S. B. Howell, K. G. Stassun, G. Zhou, C. Ziegler, F. Bouchy, C. Briceño, D. Charbonneau, K. I. Collins, G. Fűűrész, N. M. Guerrero, J. M. Jenkins, Eric L.N. Jensen, M. H. K. Kristiansen, N. Law, M. Lendl, A. W. Mann, H. P. Osborn, S. N. Quinn, G. R. Ricker, R. P. Schwarz, S. Seager, E. B. Ting, R. Vanderspek, D. Watanabe, J. N. Winn
Separated Twins Or Just Siblings? A Multiplanet System Around An M Dwarf Including A Cool Sub-Neptune, M. Harris, D. Dragomir, I. Mireles, K. A. Collins, S. Ulmer-Moll, S. B. Howell, K. G. Stassun, G. Zhou, C. Ziegler, F. Bouchy, C. Briceño, D. Charbonneau, K. I. Collins, G. Fűűrész, N. M. Guerrero, J. M. Jenkins, Eric L.N. Jensen, M. H. K. Kristiansen, N. Law, M. Lendl, A. W. Mann, H. P. Osborn, S. N. Quinn, G. R. Ricker, R. P. Schwarz, S. Seager, E. B. Ting, R. Vanderspek, D. Watanabe, J. N. Winn
Physics & Astronomy Faculty Works
We report the discovery of two TESS sub-Neptunes orbiting the early M dwarf TOI-904 (TIC 261257684). Both exoplanets, TOI-904 b and c, were initially observed in TESS Sector 12 with twin sizes of 2.426 (+0.163)/(-0.157) and 2.167 (+0.130)/(-0.118) R⊕, respectively. Through observations in five additional sectors in the TESS primary mission and the first and second extended missions, the orbital periods of the planets were measured to be 10.887 ± 0.001 and 83.999 ± 0.001 days, respectively. Reconnaissance radial velocity measurements (taken with EULER/CORALIE and SMARTS/CHIRON) and high-resolution speckle imaging with adaptive optics (obtained from SOAR/HRCAM and Gemini …
Assessing The Robustness Of Sound Horizon-Free Determinations Of The Hubble Constant, Tristan L. Smith, V. Poulin, T. Simon
Assessing The Robustness Of Sound Horizon-Free Determinations Of The Hubble Constant, Tristan L. Smith, V. Poulin, T. Simon
Physics & Astronomy Faculty Works
The Hubble tension can be addressed by modifying the sound horizon (rs) before recombination, triggering interest in early universe estimates of the Hubble constant, H0, independent of rs. Constraints on H0 from an rs-free analysis of the full shape BOSS galaxy power spectra within Λ CDM were recently reported and used to comment on the viability of physics beyond Λ CDM. Here we demonstrate that rs-free analyses with current data depend on both the model and the priors placed on the cosmological parameters, such that Λ CDM analyses …
Magnetic-Field-Driven Director Configuration Transitions In Radial Nematic Liquid Crystal Droplets, S. Ettinger, C. G. Slaughter, S. H. Parra, J. M. Kikkawa, Peter J. Collings, A. G. Yodh
Magnetic-Field-Driven Director Configuration Transitions In Radial Nematic Liquid Crystal Droplets, S. Ettinger, C. G. Slaughter, S. H. Parra, J. M. Kikkawa, Peter J. Collings, A. G. Yodh
Physics & Astronomy Faculty Works
We study the director configurations of nematic liquid crystal (NLC) droplets with homeotropic anchoring in a magnetic field and report observation of a magnetic-field-driven transition from a deformed radial to an axial-with-defect configuration. Magnetic-field-induced transitions in NLC droplets differ fundamentally from the traditional planar Freedericksz transition due to the spherical droplet geometry and resulting topological defect. This transition has been studied theoretically, but the director configurations and mechanism of defect evolution in an applied magnetic field have yet to be observed experimentally. To this end, we combine polarized optical microscopy with a variable electromagnet (≤ 1 T) for continuous observation …
Development And Reliability Analysis Of A Split-Administration Test Of The Math Epistemic Games Survey, Stephen Hackler, E. Elliott, M. Eichenlaub, A. M. Sweeney
Development And Reliability Analysis Of A Split-Administration Test Of The Math Epistemic Games Survey, Stephen Hackler, E. Elliott, M. Eichenlaub, A. M. Sweeney
Physics & Astronomy Faculty Works
The increasing and diversifying student enrollments in introductory physics courses make reliable, valid, and usable instruments for measuring student skills and gains ever more important. In introductory physics, in addition to teaching facts about mechanics, we also seek to teach our students the skills of “thinking like a physicist,” or expertise in and intuition for physical problem solving. How and when these expert, intuitive problem-solving skills emerge during a STEM education, or what the most effective teaching methods might be, are not certain. A facile survey to measure students’ “physics-thinking” skills in a pretest and post-test format is therefore desirable …
Development And Reliability Analysis Of A Split-Administration Test Of The Math Epistemic Games Survey, Stephen Hackler, E. Elliott, M. Eichenlaub, Alison M. Sweeney
Development And Reliability Analysis Of A Split-Administration Test Of The Math Epistemic Games Survey, Stephen Hackler, E. Elliott, M. Eichenlaub, Alison M. Sweeney
Physics & Astronomy Faculty Works
The increasing and diversifying student enrollments in introductory physics courses make reliable, valid, and usable instruments for measuring student skills and gains ever more important. In introductory physics, in addition to teaching facts about mechanics, we also seek to teach our students the skills of “thinking like a physicist,” or expertise in and intuition for physical problem solving. How and when these expert, intuitive problem-solving skills emerge during a STEM education, or what the most effective teaching methods might be, are not certain. A facile survey to measure students’ “physics-thinking” skills in a pretest and post-test format is therefore desirable …
Consistency Of Effective Field Theory Analyses Of The Boss Power Spectrum, T. Simon, P. Zhang, V. Poulin, Tristan L. Smith
Consistency Of Effective Field Theory Analyses Of The Boss Power Spectrum, T. Simon, P. Zhang, V. Poulin, Tristan L. Smith
Physics & Astronomy Faculty Works
We assess the robustness of Λ cold dark matter (Λ CDM) results from the full-shape analysis of BOSS power spectrum using the one-loop prediction of the effective field theory of large-scale structure (EFTofLSS). In former EFT analyses, the two public likelihoods pybird and class-pt lead to results in agreement only at the 1σ level, which may appear unsatisfactory given that they are derived from the same BOSS dataset and the same theory model. To identify the origin of the difference, we perform a thorough comparison of the various analyses choices made between the two pipelines. We find that most …
Updated Constraints From The Effective Field Theory Analysis Of The Boss Power Spectrum On Early Dark Energy, T. Simon, P. Zhang, V. Poulin, Tristan L. Smith
Updated Constraints From The Effective Field Theory Analysis Of The Boss Power Spectrum On Early Dark Energy, T. Simon, P. Zhang, V. Poulin, Tristan L. Smith
Physics & Astronomy Faculty Works
Analyses of the full shape of the Baryon Oscillation Spectroscopic Survey (BOSS) DR12 power spectrum using the one-loop prediction from the effective field theory of large-scale structures (EFTBOSS) have led to new constraints on extensions to the Λ cold dark matter model, such as early dark energy (EDE), which has been suggested as a resolution to the “Hubble tension.” In this paper, we reassess the constraining power of the EFTBOSS on EDE in light of a correction to the normalization of BOSS window functions. Overall we find that constraints from EFTBOSS on EDE are weakened and represent a small change …
Development Of A Biaxial Apparatus For Jamming Profiles Of Photoelastic Granular Media, H. Zheng, G. Dai, Cacey Stevens Bester, M. Wang, D. Wang
Development Of A Biaxial Apparatus For Jamming Profiles Of Photoelastic Granular Media, H. Zheng, G. Dai, Cacey Stevens Bester, M. Wang, D. Wang
Physics & Astronomy Faculty Works
We describe a two-dimensional biaxial apparatus that is used to conduct the experimental study of the jamming of granular media. The setup is designed based on the photoelastic imaging technique, which allows us to detect force-bearing contacts among particles, calculate the pressure on each particle according to the mean squared intensity gradient method, and compute contact forces on each particle [T. S. Majmudar and R. P. Behringer, Nature 435, 1079–1082 (2005)]. Particles float in a density-matched solution to avoid basal friction during experiments. We can compress (uniaxially or biaxially) or shear the granular system by an entangled comb geometry by …
Nonharmonic Contributions To The High-Temperature Phonon Thermodynamics Of Cr, C. M. Bernal-Choban, Hillary L. Smith, C. N. Saunders, D. S. Kim, D. L. Abernathy, B. Fultz
Nonharmonic Contributions To The High-Temperature Phonon Thermodynamics Of Cr, C. M. Bernal-Choban, Hillary L. Smith, C. N. Saunders, D. S. Kim, D. L. Abernathy, B. Fultz
Physics & Astronomy Faculty Works
Phonon densities of states (DOSs) of body-centered cubic chromium were measured by time-of-flight inelastic neutron scattering at temperatures up to 1493 K. Density functional theory calculations with both quasiharmonic (QH) and anharmonic (AH) methods were performed at temperatures above the Néel temperature. Features in the phonon DOSs decrease in energy (soften) substantially with temperature. A Born–von Kármán analysis using fits to the experimental DOSs reveals a softening of almost 17% of the high-transverse phonon branch between 330 and 1493 K. The low-transverse branch changes by approximately half this amount. The AH calculations capture the observed behavior of the two transverse …
Was Entropy Conserved Between Bbn And Recombination?, A. C. Sobotka, A. L. Erickcek, Tristan L. Smith
Was Entropy Conserved Between Bbn And Recombination?, A. C. Sobotka, A. L. Erickcek, Tristan L. Smith
Physics & Astronomy Faculty Works
We test the assumption of entropy conservation between big bang nucleosynthesis and recombination by considering a massive particle that decays into a mixture of photons and other relativistic species. We employ Planck temperature and polarization anisotropies, COBE/FIRAS spectral distortion bounds, and the observed primordial deuterium abundance to constrain these decay scenarios. If between 56% and 71% of the decaying particle’s energy is transferred to photons, then Neff at recombination is minimally altered, and Planck data alone allows for significant entropy injection. If photons are injected by the decay, the addition of spectral distortion bounds restricts the decay rate of …