
NSF Org: |
PHY Division Of Physics |
Recipient: |
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Initial Amendment Date: | June 20, 2018 |
Latest Amendment Date: | August 7, 2024 |
Award Number: | 1748621 |
Award Instrument: | Continuing Grant |
Program Manager: |
Bogdan Mihaila
bmihaila@nsf.gov (703)292-8235 PHY Division Of Physics MPS Directorate for Mathematical and Physical Sciences |
Start Date: | July 1, 2018 |
End Date: | October 31, 2024 (Estimated) |
Total Intended Award Amount: | $425,000.00 |
Total Awarded Amount to Date: | $549,998.00 |
Funds Obligated to Date: |
FY 2019 = $85,000.00 FY 2020 = $85,000.00 FY 2021 = $209,999.00 FY 2023 = $84,999.00 |
History of Investigator: |
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Recipient Sponsored Research Office: |
1500 HORNING RD KENT OH US 44242-0001 (330)672-2070 |
Sponsor Congressional District: |
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Primary Place of Performance: |
Physics Dept. PO Box 5190 Kent OH US 44242-0001 |
Primary Place of
Performance Congressional District: |
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Unique Entity Identifier (UEI): |
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Parent UEI: |
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NSF Program(s): | NUCLEAR THEORY |
Primary Program Source: |
01001920DB NSF RESEARCH & RELATED ACTIVIT 01002021DB NSF RESEARCH & RELATED ACTIVIT 01002122DB NSF RESEARCH & RELATED ACTIVIT 01002223DB NSF RESEARCH & RELATED ACTIVIT 01002324DB NSF RESEARCH & RELATED ACTIVIT 01002021DB NSF RESEARCH & RELATED ACTIVIT 01002122DB NSF RESEARCH & RELATED ACTIVIT |
Program Reference Code(s): |
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Program Element Code(s): |
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Award Agency Code: | 4900 |
Fund Agency Code: | 4900 |
Assistance Listing Number(s): | 47.049 |
ABSTRACT
With the exception of black holes, neutron stars are the densest objects in the Universe. Inside these objects, exotic particles such as hyperons and deconfined quarks that do not exist in a stable form anywhere else in the universe can be created. This project proposes an in-depth investigation of new kinds of matter inside neutron stars as well as the effects of incredibly strong magnetic fields, many orders of magnitude larger than the one present inside the Sun, on these phases of matter. The results of this research will be used by the astrophysics community to search for clear signals of stable exotic matter in neutrinos bursts and gravitational waves. The project involves the training of high school, undergraduate and graduate students in astrophysics research, and includes a series of seminars open for the community that highlights the role of female astrophysicists.
The project will pursue an extension of a realistic description of hadronic and quark phases in the core of neutron stars to include magnetic fields together with finite temperature effects. This will enable effects of strong magnetic fields to be studied in different regions of stars, not only for cold neutron stars but also for proto-neutron stars. For the latter case, this project will also study the effects of neutrinos and entropy per particle on the structure of phase transitions. With these ingredients in hand, complete data tables will be built from a realistic equation of state to be used by others in dynamical simulations of supernova explosions, compact binary mergers, and neutron star cooling, to answer a fundamental question in astrophysics: Do exotic degrees of freedom play a role in the above phenomena? Having the first extensive data table built from a single realistic description will be extremely useful and allow for more accurate dynamical calculations of astrophysical phenomena. The students involved in the project will make meaningful contributions to state-of-the-art research. Finally, this project will support a series of seminars open for the community that highlights the role of female astrophysicists.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
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PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
In this project, we studied dense matter at finite temperature, focusing on deconfinement to quark matter, the most important feature predicted by Quantum Chromodynamics (QCD) to take place at high energy. We quantified the effects of strangeness, isospin, different strong-force couplings, deconfinement phase-transition strengths, and magnetic fields. We constructed multidimensional QCD phase diagrams highlighting trajectories followed by neutron stars, proto-neutron stars, neutron star mergers, and laboratory particle collisions of different energies. We concluded that, once the exact conditions are found for deconfinement to take place in the laboratory at large densities (a given baryon chemical potential and temperature), this has to be carefully translated to the conditions in astrophysical scenarios, as both net strangeness and isospin affect the deconfinement baryon chemical potential and temperature by tens of MeV’s. The same can also be said for the case that the exact conditions are found for deconfinement in astrophysics. In the latter case, we also found a smoking gun for deconfinement in neutron star mergers, by identifying together with our collaborators that a strong first-order phase transition to deconfined quark matter would shorten the post-merger gravitational wave signal, without affecting the pre-merger signal. This could be soon measured by the LIGO-Virgo collaborations.
This work produced data tables with the description of dense matter that were made available for the entire scientific community through the CompOSE repository. These have already been used by several groups around the globe to e.g., study the effects of temperature on the production of strange particles and run simulations of stellar cooling. Our group used our description to investigate in addition magnetic white dwarfs, the possibility of magnetic twin stars, the role of spin 3/2 resonances in magnetic stars, fast rotating neutron stars, and the possibility of reproducing very massive or small neutron stars. We made successful comparisons with lattice QCD, perturbative QCD and other models, such as the PNJL. We investigated how physics at lower density (that can be more easily be studied in the laboratory) can affect astrophysics, e.g., by investigating the effects of the symmetry energy or hyperon potentials in dense matter and on quark deconfinement and the QCD phase diagram. We also studied in detail which kind of nuclear interactions, especially the ones that give rise to repulsion, are necessary to reproduce the conditions observed in specific observations of neutron stars and their mergers, both made electromagnetically and gravitationally. We found that those necessarily include higher-order terms and mixed terms that contain isospin.
We completed 3 PhD theses and published 51 papers and conference proceedings (being 3 selected as Editor’s suggestion and 4 published as letters). We delivered many talks to the scientific community discussing this project’s results in conferences, workshops, universities, and laboratories, in addition to graduate summer schools. To reach a larger audience, several public lectures in e.g., libraries were delivered. The project involved the PI, one postdoc, and three graduate students, in addition to several undergraduate students and high school students. This project also included a series of events to highlight the work of female astrophysicists, as a way to attract more young girls into science. Unfortunately, many of the planed events were canceled due to the COVID pandemic. Still, we managed to organize several colloquia, in addition to one "Science Cafe" at a local coffee shop, lunches with undergraduate and graduate female students, an event organized to bring for middle school girls from the Ohio public school system to the university called WOMEN IN STEM DAY, and an event in collaboration with the local Women's Center to discuss the role of African-American women in our society.
Last Modified: 02/28/2025
Modified by: Veronica Dexheimer
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