The transport properties of dense QCD matter play a crucial role in the physics of neutron stars and their mergers but are notoriously difficult to study with traditional quantum field theory tools. Specializing to the case of unpaired quark matter in beta equilibrium, we approach the problem through the machinery of holography, in particular the V-QCD and D3-D7 models, and derive results for the electrical and thermal conductivities and the shear and bulk viscosities. In addition we compare the bulk to shear viscosity ratio to the speed of sound and find that it violates the so-called Buchel bound. Our results differ dramatically from earlier predictions of perturbative QCD, the root causes and implications of which we analyze in detail.
{ "_oai": { "updated": "2022-04-05T10:19:14Z", "id": "oai:repo.scoap3.org:68611", "sets": [ "PRD" ] }, "authors": [ { "raw_name": "Carlos Hoyos", "affiliations": [ { "country": "Spain", "value": "Department of Physics, Universidad de Oviedo and Instituto de Ciencias y Tecnologi\u0301as Espaciales de Asturias (ICTEA), C/ Federico Garc\u00eda Lorca 18, ES-33007 Oviedo, Spain" } ], "surname": "Hoyos", "given_names": "Carlos", "full_name": "Hoyos, Carlos" }, { "raw_name": "Niko Jokela", "affiliations": [ { "country": "Finland", "value": "Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 University of Helsinki, Finland" } ], "surname": "Jokela", "given_names": "Niko", "full_name": "Jokela, Niko" }, { "raw_name": "Matti J\u00e4rvinen", "affiliations": [ { "country": "South Korea", "value": "Asia Pacific Center for Theoretical Physics, Pohang 37673, Republic of Korea" }, { "country": "South Korea", "value": "Department of Physics, Pohang University of Science and Technology, Pohang 37673, Republic of Korea" } ], "surname": "J\u00e4rvinen", "given_names": "Matti", "full_name": "J\u00e4rvinen, Matti" }, { "raw_name": "Javier G. Subils", "affiliations": [ { "country": "Spain", "value": "Departament de F\u00edsica Qu\u00e0ntica i Astrof\u00edsica and Institut de Ci\u00e8ncies del Cosmos (ICC), Universitat de Barcelona, Mart\u00ed Franqu\u00e8s 1, ES-08028 Barcelona, Spain" }, { "country": "Sweden", "value": "Nordita KTH Royal Institute of Technology and Stockholm University, Hannes Alfv\u00e9ns v\u00e4g 12, SE-106 91 Stockholm, Sweden" } ], "surname": "Subils", "given_names": "Javier G.", "full_name": "Subils, Javier G." }, { "raw_name": "Javier Tarr\u00edo", "affiliations": [ { "country": "Finland", "value": "Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 University of Helsinki, Finland" } ], "surname": "Tarr\u00edo", "given_names": "Javier", "full_name": "Tarr\u00edo, Javier" }, { "raw_name": "Aleksi Vuorinen", "affiliations": [ { "country": "Finland", "value": "Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 University of Helsinki, Finland" } ], "surname": "Vuorinen", "given_names": "Aleksi", "full_name": "Vuorinen, Aleksi" } ], "titles": [ { "source": "APS", "title": "Holographic approach to transport in dense QCD matter" } ], "dois": [ { "value": "10.1103/PhysRevD.105.066014" } ], "publication_info": [ { "journal_volume": "105", "journal_title": "Physical Review D", "material": "article", "journal_issue": "6", "year": 2022 } ], "$schema": "http://repo.scoap3.org/schemas/hep.json", "acquisition_source": { "date": "2022-04-05T09:26:21.632239", "source": "APS", "method": "APS", "submission_number": "3dc63052b4c211ec837fd6d834be26e1" }, "page_nr": [ 27 ], "license": [ { "url": "https://creativecommons.org/licenses/by/4.0/", "license": "CC-BY-4.0" } ], "copyright": [ { "statement": "Published by the American Physical Society", "year": "2022" } ], "control_number": "68611", "record_creation_date": "2022-03-25T16:30:06.859505", "_files": [ { "checksum": "md5:4ae44097b301326b1a356973d5ce9322", "filetype": "pdf", "bucket": "2b1e5a70-08ec-43ee-980b-44b6372e34b6", "version_id": "3e977599-b7da-4179-8349-bb83f7af1ac3", "key": "10.1103/PhysRevD.105.066014.pdf", "size": 1351682 }, { "checksum": "md5:236a5f06b5bc4a927e70efbdaf1f26da", "filetype": "xml", "bucket": "2b1e5a70-08ec-43ee-980b-44b6372e34b6", "version_id": "fd170ecc-85be-4ec3-9e79-b684fe96ef64", "key": "10.1103/PhysRevD.105.066014.xml", "size": 524788 } ], "collections": [ { "primary": "HEP" }, { "primary": "Citeable" }, { "primary": "Published" } ], "arxiv_eprints": [ { "categories": [ "hep-th", "astro-ph.HE", "hep-ph", "nucl-th" ], "value": "2109.12122" } ], "abstracts": [ { "source": "APS", "value": "The transport properties of dense QCD matter play a crucial role in the physics of neutron stars and their mergers but are notoriously difficult to study with traditional quantum field theory tools. Specializing to the case of unpaired quark matter in beta equilibrium, we approach the problem through the machinery of holography, in particular the V-QCD and D3-D7 models, and derive results for the electrical and thermal conductivities and the shear and bulk viscosities. In addition we compare the bulk to shear viscosity ratio to the speed of sound and find that it violates the so-called Buchel bound. Our results differ dramatically from earlier predictions of perturbative QCD, the root causes and implications of which we analyze in detail." } ], "imprints": [ { "date": "2022-03-25", "publisher": "APS" } ] }