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Author Fourdrinoy, J.; Robertson, S.; James, N.; Fabbri, A.; Rousseaux, G.
Title Correlations on weakly time-dependent transcritical white-hole flows Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 105 Issue 8 Pages (up) 085022 - 14pp
Keywords
Abstract We report observations made on a run of transcritical flows over an obstacle in a narrow channel. Downstream from the obstacle, the flows decelerate from supercritical to subcritical, typically with an undulation on the subcritical side (known in hydrodynamics as an undular hydraulic jump). In the Analogue Gravity context, this transition corresponds to a white-hole horizon. Free-surface deformations are analyzed, mainly via the two-point correlation function which shows the presence of a checkerboard pattern in the vicinity of the undulation. In nongated flows where the white-hole horizon occurs far downstream from the obstacle, this checkerboard pattern is shown to be due to low-frequency fluctuations associated with slow longitudinal movement of the undulation. Tt can thus be considered as an artifact due to a time-varying background. In gated flows, however, the undulation is typically “attached” to the obstacle, and the fluctuations associated with its movement are strongly suppressed. In this case, the observed correlation pattern is likely due to a stochastic ensemble of surface waves, scattering on a background that is essentially stationary.
Address [Fourdrinoy, Johan; Rousseaux, Germain] Univ Poitiers, CNRS, Inst Pprime, ISAL ENSMA, TSA 51124, F-86073 Poitiers 9, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000810510200011 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5274
Permanent link to this record
 
 
Author Clement, G.; Fabbri, A.
Title A scenario for critical scalar field collapse in AdS(3) Type Journal Article
Year 2015 Publication Classical and Quantum Gravity Abbreviated Journal Class. Quantum Gravity
Volume 32 Issue 9 Pages (up) 095009 - 16pp
Keywords critical collapse; exact solutions; AdS(3)
Abstract We present a family of exact solutions, depending on two parameters alpha and b (related to the scalar field strength), to the three-dimensional Einstein-scalar field equations with negative cosmological constant Lambda. For b not equal 0 these solutions reduce to the static Banados-Teitelboim-Zanelli (BTZ) family of vacuum solutions, with mass M = -alpha. For b not equal 0, the solutions become dynamical and develop a strong spacelike central singularity. The alpha < 0 solutions are black-hole like, with a global structure topologically similar to that of the BTZ black holes, and a finite effective mass. We show that the near-singularity behavior of the solutions with alpha > 0 agrees qualitatively with that observed in numerical simulations of sub-critical collapse, including the independence of the near-critical regime on the angle deficit of the spacetime. We analyze in the Lambda = 0 approximation the linear perturbations of the self-similar threshold solution, alpha = 0, and find that it has only one unstable growing mode, which qualifies it as a candidate critical solution for scalar field collapse.
Address [Clement, Gerard] Univ Savoie, CNRS, LAPTh, F-74941 Annecy Le Vieux, France, Email: gerard.clement@lapth.cnrs.fr;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-9381 ISBN Medium
Area Expedition Conference
Notes WOS:000353351500009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2192
Permanent link to this record
 
 
Author Casals, M.; Fabbri, A.; Martinez, C.; Zanelli, J.
Title Quantum-corrected rotating black holes and naked singularities in (2+1) dimensions Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 10 Pages (up) 104023 - 39pp
Keywords
Abstract We analytically investigate the perturbative effects of a quantum conformally coupled scalar field on rotating (2 + 1)-dimensional black holes and naked singularities. In both cases we obtain the quantum-back-reacted metric analytically. In the black hole case, we explore the quantum corrections on different regions of relevance for a rotating black hole geometry. We find that the quantum effects lead to a growth of both the event horizon and the ergosphere, as well as to a reduction of the angular velocity compared to their corresponding unperturbed values. Quantum corrections also give rise to the formation of a curvature singularity at the Cauchy horizon and show no evidence of the appearance of a superradiant instability. In the naked singularity case, quantum effects lead to the formation of a horizon that hides the conical defect, thus turning it into a black hole. The fact that these effects occur not only for static but also for spinning geometries makes a strong case for the role of quantum mechanics as a cosmic censor in Nature.
Address [Casals, Marc] CBPF, BR-22290180 Rio De Janeiro, Brazil, Email: mcasals@cbpf.br;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000509560700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4263
Permanent link to this record
 
 
Author Anderson, P.R.; Balbinot, R.; Fabbri, A.; Parentani, R.
Title Gray-body factor and infrared divergences in 1D BEC acoustic black holes Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 90 Issue 10 Pages (up) 104044 - 6pp
Keywords
Abstract It is shown that the gray-body factor for a one-dimensional elongated Bose-Einstein condensate (BEC) acoustic black hole with one horizon does not vanish in the low-frequency (omega -> 0) limit. This implies that the analog Hawking radiation is dominated by the emission of an infinite number (1/omega) of soft phonons in contrast with the case of a Schwarzschild black hole where the gray-body factor vanishes as omega -> 0 and the spectrum is not dominated by low-energy particles. The infrared behaviors of certain correlation functions are also discussed.
Address [Anderson, Paul R.] Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA, Email: anderson@wfu.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000348186700004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2079
Permanent link to this record
 
 
Author Dudley, R.A.; Fabbri, A.; Anderson, P.R.; Balbinot, R.
Title Correlations between a Hawking particle and its partner in a 1+1D Bose-Einstein condensate analog black hole Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 102 Issue 10 Pages (up) 105005 - 12pp
Keywords
Abstract The Fourier transform of the density-density correlation function in a Bose-Einstein condensate (BEC) analog black hole is a useful tool to investigate correlations between the Hawking particles and their partners. It can be expressed in terms of <(out)(a) over cap (ext)(up) (out)(a) over cap (int)(up)> where (out)(a) over cap (ext)(up) is the annihilation operator for the Hawking particle and (out)(a) over cap (int)(up) is the corresponding one for the partner. This basic quantity is calculated for three different models for the BEC flow. It is shown that in each model the inclusion of the effective potential in the mode equations makes a significant difference. Furthermore, particle production induced by this effective potential in the interior of the black hole is studied for each model and shown to be nonthermal. An interesting peak that is related to the particle production and is present in some models is discussed.
Address [Dudley, Richard A.; Anderson, Paul R.] Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA, Email: dudlra13@wfu.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000584963300005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4590
Permanent link to this record
 
 
Author Balbinot, R.; Fabbri, A.; Dudley, R.A.; Anderson, P.R.
Title Particle production in the interiors of acoustic black holes Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 10 Pages (up) 105021 - 13pp
Keywords
Abstract Phonon creation inside the horizons of acoustic black holes is investigated using two simple toy models. It is shown that, unlike what occurs in the exterior regions, the spectrum is not thermal. This nonthermality is due to the anomalous scattering that occurs in the interior regions.
Address [Balbinot, Roberto] Univ Bologna, Dipartimento Fis, Via Irnerio 46, I-40126 Bologna, Italy, Email: balbinot@bo.infn.it;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000498879600007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4209
Permanent link to this record
 
 
Author Fabbri, A.; Balbinot, R.
Title Ramp-up of Hawking Radiation in Bose-Einstein-Condensate Analog Black Holes Type Journal Article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 126 Issue 11 Pages (up) 111301 - 6pp
Keywords
Abstract Inspired by a recent experiment by Steinhauer and co-workers, we present a simple model which describes the formation of an acoustic black hole in a Bose-Einstein condensate, allowing an analytical computation of the evolution in time of the corresponding density-density correlator. We show the emergence of analog Hawking radiation out of a “quantum atmosphere” region significantly displaced from the horizon. This is quantitatively studied both at T = 0 and even in the presence of an initial temperature T, as is always the case experimentally.
Address [Fabbri, Alessandro] Ctr Mixto Univ Valencia, CSIC, Dept Fis Teor, C Dr Moliner 50, Burjassot 46100, Spain, Email: afabbri@ific.uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000652825400006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4842
Permanent link to this record
 
 
Author Dudley, R.A.; Anderson, P.R.; Balbinot, R.; Fabbri, A.
Title Correlation patterns from massive phonons in 1+1 dimensional acoustic black holes: A toy model Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 12 Pages (up) 124011 - 18pp
Keywords
Abstract Transverse excitations in analogue black holes induce a masslike term in the longitudinal mode equation. With a simple toy model we show that correlation functions display a rather rich structure characterized by groups of approximately parallel peaks. For the most part the structure is completely different from that found in the massless case.
Address [Dudley, Richard A.; Anderson, Paul R.] Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA, Email: dudlra13@wfu.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000452979300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3834
Permanent link to this record
 
 
Author Fabbri, A.; Mayoral, C.
Title Steplike discontinuities in Bose-Einstein condensates and Hawking radiation: The hydrodynamic limit Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 83 Issue 12 Pages (up) 124016 - 14pp
Keywords
Abstract We present a detailed analytical analysis of the propagation of Bogoliubov phonons on top of Bose-Einstein condensates with spatial and temporal steplike discontinuities in the speed of sound in the hydrodynamic limit. We focus on some features in the correlations patterns, in particular, of density-density correlations. The application to the study of the Hawking signal in the formation of acoustic black hole-like configurations is also discussed.
Address [Fabbri, Alessandro] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: afabbri@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes ISI:000291353700008 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 640
Permanent link to this record
 
 
Author Anderson, P.R.; Balbinot, R.; Fabbri, A.; Parentani, R.
Title Hawking radiation correlations in Bose-Einstein condensates using quantum field theory in curved space Type Journal Article
Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 87 Issue 12 Pages (up) 124018 - 18pp
Keywords
Abstract The density-density correlation function is computed for the Bogoliubov pseudoparticles created in a Bose-Einstein condensate undergoing a black hole flow. On the basis of the gravitational analogy, the method used relies only on quantum field theory in curved spacetime techniques. A comparison with the results obtained by ab initio full condensed matter calculations is given, confirming the validity of the approximation used, provided the profile of the flow varies smoothly on scales compared to the condensate healing length.
Address [Anderson, Paul R.] Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA, Email: anderson@wfu.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000320609200009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1488
Permanent link to this record