Astrophysics and Astronomy Commons^™

Exiting Inflation With A Smooth Scale Factor, Harry Oslislo, Brett Altschul

Faculty Publications

The expectation that the physical expansion of space occurs smoothly may be expressed mathematically as a requirement for continuity in the time derivative of the metric scale factor of the Friedmann–Robertson–Walker cosmology. We explore the consequences of imposing such a smoothness requirement, examining the forms of possible interpolating functions between the end of inflation and subsequent radiation- or matter-dominated eras, using a straightforward geometric model of the interpolating behavior. We quantify the magnitude of the cusp found in a direct transition from the end of slow-roll inflation to the subsequent era, analyze the validity of several smooth interpolator candidates, and …

Core Destruction In Knockout Reactions, Carlos A. Bertulani

Faculty Publications

A model is presented to calculate projectile core destruction in knockout reactions. It incorporates physics arguments similar to the formulation of the state of the art theory to calculate stripping and diffraction dissociation cross sections in heavy ion collisions with bombarding energies around 100 MeV/nucleon and larger. It is shown that secondary collisions between the incoming and struck nucleons with the projectile core decrease the core survival probability by as much as 9.5%. However, no clear evidence is found for reduction of the cross section with increasing binding energy of the removed nucleon.

Core States Of Neutron Stars From Anatomizing Their Scaled Structure Equations, Bao-Jun Cai, Bao-An Li, Zen Zhang

Faculty Publications

Given an Equation of State (EOS) for neutron star (NS) matter, there is a unique mass–radius sequence characterized by a maximum mass MNS max at radius Rmax. We first show analytically that the MNS max and Rmax scale linearly with two different combinations of the NS central pressure Pc and energy densityεc, by dissecting perturbatively the dimension less Tolman–Oppenheimer–Volkoff (TOV) equations governing NS internal variables. The scaling relations are then verified via 87 widely used and rather diverse phenomenological as well as 17 microscopic NS EOSs with/without considering hadron–quark phase transitions and hyperons, by solving numerically the original TOV equations. …

Complexity Heliophysics: A [New] System Science That Transcends The Previous Boundaries Of Our Field, Ryan M. Mcgranaghan, Seebany Datta-Barua, Jeffrey Thayer, Joe Borovsky, Jay R. Johnson, Simon Wing, Dan Baker, Massimo Materassi

Faculty Publications

Synopsis

1. The 21st century is the time of complexity. We delineate it and its importance as necessary to solve ‘wicked problems.’

2. Inherently transdisciplinary, trans-scale, and interconnected to living systems, the solution to Heliophysics’ identity crisis and to unlock the next generation of scientific discovery may be to embrace complexity.

3. With the right foresight, direction, and incentive over the next ten years, Heliophysics can become a beacon for how all of society thinks about and does complexity science.

Perturbative Aspects Of Cpt-Even Lorentz-Violating Scalar Chromodynamics, Brett Altschul, L. C.T. Brito, J. C.C. Felipe, S. Karki, A. C. Lehum, A. Yu Petrov

Faculty Publications

In this work, we formulate the theory of Lorentz-violating scalar quantum chromodynamics with an arbitrary non-Abelian gauge group. This theory belongs to the class of models encompassed by the standard model extension framework. At the lowest order in the theory's Lorentz violation parameters, we calculate the divergent quantum corrections, including the renormalization group β-functions of the theory. The Lorentz-violating sector is shown to be scale invariant if there is a particular relation between the couplings.

Seasonal And Diurnal Variations Of Kelvin-Helmholtz Instability At Terrestrial Magnetopause, S. Kavosi, J. Raeder, Jay R. Johnson, K. Nykyri, C. J. Farrugia

Faculty Publications

Kelvin-Helmholtz Instability is ubiquitous at Earth’s magnetopause and plays an important role in plasma entry into the magnetosphere during northward interplanetary magnetic fields. Here, using one solar cycle of data from NASA THEMIS (Time History of Events and Macro scale Interactions during Substorms) and MMS (Magnetospheric Multiscale) missions, we found that KHI occurrence rates show seasonal and diurnal variations with the rate being high near the equinoxes and low near the solstices. The instability depends directly on the Earth’s dipole tilt angle. The tilt toward or away from the Sun explains most of the seasonal and diurnal variations, while the …

Information Horizon Of Solar Active Regions, Jay R. Johnson, Simon Wing, Carson O'Ffill, Bishwa Neupane

Faculty Publications

Information theory is used to characterize the solar active region periodicities and memories from the Carrington map images 1974–2021. The active regions typically evolve and move from one map to the next. In order to track these active region structures in sequences of images, an innovative method based on information theory is developed. Image entropy provides a measure of the organization of structures in the images. The entropy can also be used as a filter to identify structures and partition the active regions, which are then registered for each image. The partitions are used to compute the mutual information and …

Measurement Of The Double-Differential Muon-Neutrino Charged-Current Inclusive Cross Section In The Nova Near Detector, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, B. Behera, R. Bernstein, V. Bhatnagar, D. Bhattarai, B. Bhuyan, Roberto Petti, Et. Al.

Faculty Publications

We report cross-section measurements of the final-state muon kinematics for ν_μ charged-current interactions in the NOvA near detector using an accumulated 8.09×10²⁰ protons on target in the NuMI beam. We present the results as a double-differential cross section in the observed outgoing muon energy and angle, as well as single-differential cross sections in the derived neutrino energy, E_ν, and square of the four-momentum transfer, Q². We compare the results to inclusive cross-section predictions from various neutrino event generators via χ² calculations using a covariance matrix that accounts for bin-to-bin correlations of systematic uncertainties. …

Off-Shell Effects In Bound Nucleons And Parton Distributions From 1H, 2H, 3H, And 3He Data, S. I. Alekhin, S. A. Kulagin, Roberto Petti

Faculty Publications

We report the results of a new global QCD analysis including deep-inelastic scattering data off ¹H, ²H, ³H, and ³He targets. Nuclear corrections are treated in terms of a nuclear convolution approach with off-shell bound nucleons. The off-shell (OS) corrections responsible for the modification of the structure functions (SFs) of bound nucleons are constrained in a global fit along with the proton parton distribution functions (PDFs) and the higher-twist (HT) terms. We investigate the proton-neutron difference for the OS correction and discuss our predictions for the SF ratio F ⁿ ₂ / F ^p ₂ and …

Evolution Of Coronal Magnetic Field Parameters During X5.4 Solar Flare, Seth H. Garland, Benjamin F. Akers, Vasyl B. Yurchyshyn, Robert D. Loper, Daniel J. Emmons

Faculty Publications

The coronal magnetic field over NOAA Active Region 11,429 during a X5.4 solar flare on 7 March 2012 is modeled using optimization based Non-Linear Force-Free Field extrapolation. Specifically, 3D magnetic fields were modeled for 11 timesteps using the 12-min cadence Solar Dynamics Observatory (SDO) Helioseismic and Magnetic Imager photospheric vector magnetic field data, spanning a time period of 1 hour before through 1 hour after the start of the flare. Using the modeled coronal magnetic field data, seven different magnetic field parameters were calculated for 3 separate regions: areas with surface |Bz| ≥ 300 G, areas of flare brightening seen …

How Noise Thresholds Affect The Information Content Of Stellar Flare Sequences, Elmer C. Rivera, Jay R. Johnson, Jonathan Homan, Simon Wing

Faculty Publications

Systems that exhibit discrete dynamics can be well described and reconstructed by considering the set of time intervals between the discrete events of the system. The Kepler satellite has cataloged light curves for many Sun-like stars, and these light curves show strong bursts in intensity that are associated with stellar flares. The waiting time between these flares describes the fundamental dynamics of the stars and is driven by physical processes, such as flux emergence. While it is rather straightforward to identify large flares, the identification of weaker flares can be challenging because of the presence of noise. A common practice …

Three- And Four-Point Functions In Cpt -Even Lorentz-Violating Scalar Qed, Brett Altschul, L. C.T. Brito, J. C.C. Felipe, S. Karki, A. C. Lehum, A. Yu Petrov

Faculty Publications

The renormalization of quantum field theories usually assumes Lorentz and gauge symmetries, besides the general restrictions imposed by unitarity and causality. However, the set of renormalizable theories can be enlarged by relaxing some of these assumptions. In this work, we consider the particular case of a CPT-preserving but Lorentz-breaking extension of scalar QED. For this theory, we calculate the one-loop radiative corrections to the three- and four-point scalar-vector vertex functions, at the lowest order in the Lorentz-violation parameters, and we explicitly verify that the resulting low-energy effective action is compatible with the usual gauge invariance requirements. With these results, we …

Measurement Of The VE- Nucleus Charged-Current Double-Differential Cross Section At 〈EV⟩ = 2.4 Gev Using Nova, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, M. Biard, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, R. Bernstein, V. Bhatnagar, D. Bhattarai, B. Bhuyan, J. Bian, Roberto Petti, Et. Al.

Faculty Publications

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×10²⁰ protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃7.4% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on Q² (squared four-momentum transfer) and energy, in the range 1  GeV≤E_νGENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the …

To The Moon: Strategic Competition In The Cislunar Region, Shawn M. Willis

Faculty Publications

China’s advancing space capabilities, particularly in the cislunar region, call for increased cislunar space domain awareness on the part of the United States. US military and civilian decisionmakers must take into account the full scope of China’s cislunar plans and capabilities as the military builds space strategies and future force designs. The United States must also increase near-term investments that support more robust cislunar space domain awareness.

Cold Atoms In Space: Community Workshop Summary And Proposed Road-Map, Iván Alonso, Cristiano Alpigiani, Brett David Altschul, Henrique Araújo, Gianluigi Arduini, Jan Arlt, Leonardo Badurina, Antun Balaž, Satvika Bandarupally, Barry C. Barish, Michele Barone, Michele Barsanti, Steven Bass, Angelo Bassi, Baptiste Battelier, Charles F. A. Baynham, Quentin Beaufils, Aleksandar Belić, Joel Bergé, Jose Bernabeu, Et. Al.

Faculty Publications

We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. …

All-Sky Search For Short Gravitational-Wave Bursts In The Third Advanced Ligo And Advanced Virgo Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

After the detection of gravitational waves from compact binary coalescences, the search for transient gravitational-wave signals with less well-defined waveforms for which matched filtering is not well suited is one of the frontiers for gravitational-wave astronomy. Broadly classified into “short” ≲1  s and “long” ≳1  s duration signals, these signals are expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary black hole coalescences. In this work, we present a search for long-duration gravitational-wave transients from Advanced LIGO and Advanced Virgo’s third observing run from April 2019 to March 2020. For this search, we use …