Compactons and their variational properties for degenerate KdV and NLS in dimension 1
Authors:
Pierre Germain, Benjamin Harrop-Griffiths and Jeremy L. Marzuola
Journal:
Quart. Appl. Math. 78 (2020), 1-32
MSC (2010):
Primary 35Q53, 35Q55
DOI:
https://doi.org/10.1090/qam/1538
Published electronically:
April 17, 2019
MathSciNet review:
4042218
Full-text PDF
Abstract |
References |
Similar Articles |
Additional Information
Abstract: We analyze the stationary and traveling wave solutions to a family of degenerate dispersive equations of KdV- and NLS-type. In stark contrast to the standard soliton solutions for nondegenerate KdV and NLS equations, the degeneracy of the elliptic operators studied here allows for compactly supported steady or traveling states. As we work in $1$ dimension, ODE methods apply; however, the models considered have formally conserved Hamiltonian, Mass, and Momentum functionals, which allow for variational analysis as well.
References
- David M. Ambrose, Gideon Simpson, J. Douglas Wright, and Dennis G. Yang, Ill-posedness of degenerate dispersive equations, Nonlinearity 25 (2012), no. 9, 2655–2680. MR 2967120, DOI https://doi.org/10.1088/0951-7715/25/9/2655
- H. Berestycki and P.-L. Lions, Nonlinear scalar field equations. I. Existence of a ground state, Arch. Rational Mech. Anal. 82 (1983), no. 4, 313–345. MR 695535, DOI https://doi.org/10.1007/BF00250555
- F. Betancourt, R. Bürger, K. H. Karlsen, and E. M. Tory, On nonlocal conservation laws modelling sedimentation, Nonlinearity 24 (2011), no. 3, 855–885. MR 2772627, DOI https://doi.org/10.1088/0951-7715/24/3/008
- Joseph Biello and John K. Hunter, Nonlinear Hamiltonian waves with constant frequency and surface waves on vorticity discontinuities, Comm. Pure Appl. Math. 63 (2010), no. 3, 303–336. MR 2599457, DOI https://doi.org/10.1002/cpa.20304
- Jerry L. Bona, Shu Ming Sun, and Bing-Yu Zhang, A nonhomogeneous boundary-value problem for the Korteweg-de Vries equation posed on a finite domain, Comm. Partial Differential Equations 28 (2003), no. 7-8, 1391–1436. MR 1998942, DOI https://doi.org/10.1081/PDE-120024373
- M. Burak Erdoğan and Wilhelm Schlag, Dispersive estimates for Schrödinger operators in the presence of a resonance and/or an eigenvalue at zero energy in dimension three. II, J. Anal. Math. 99 (2006), 199–248. MR 2279551, DOI https://doi.org/10.1007/BF02789446
- Miguel Andres Caicedo and Bing-Yu Zhang, Well-posedness of a nonlinear boundary value problem for the Korteweg–de Vries equation on a bounded domain, J. Math. Anal. Appl. 448 (2017), no. 2, 797–814. MR 3582261, DOI https://doi.org/10.1016/j.jmaa.2016.11.032
- Roberto Camassa and Darryl D. Holm, An integrable shallow water equation with peaked solitons, Phys. Rev. Lett. 71 (1993), no. 11, 1661–1664. MR 1234453, DOI https://doi.org/10.1103/PhysRevLett.71.1661
- Hans Christianson, Jeremy Marzuola, Jason Metcalfe, and Michael Taylor, Nonlinear bound states on weakly homogeneous spaces, Comm. Partial Differential Equations 39 (2014), no. 1, 34–97. MR 3169779, DOI https://doi.org/10.1080/03605302.2013.845044
- James E. Colliander, Jeremy L. Marzuola, Tadahiro Oh, and Gideon Simpson, Behavior of a model dynamical system with applications to weak turbulence, Exp. Math. 22 (2013), no. 3, 250–264. MR 3171091, DOI https://doi.org/10.1080/10586458.2013.793110
- Fred Cooper, Harvey Shepard, and Pasquale Sodano, Solitary waves in a class of generalized Korteweg-de Vries equations, Phys. Rev. E (3) 48 (1993), no. 5, 4027–4032. MR 1376975, DOI https://doi.org/10.1103/PhysRevE.48.4027
- Hui-Hui Dai and Yi Huo, Solitary shock waves and other travelling waves in a general compressible hyperelastic rod, R. Soc. Lond. Proc. Ser. A Math. Phys. Eng. Sci. 456 (2000), no. 1994, 331–363. MR 1811323, DOI https://doi.org/10.1098/rspa.2000.0520
- G. A. El, M. A. Hoefer, and M. Shearer, Dispersive and diffusive-dispersive shock waves for nonconvex conservation laws, SIAM Rev. 59 (2017), no. 1, 3–61. MR 3605824, DOI https://doi.org/10.1137/15M1015650
- Daniel Grieser, Basics of the $b$-calculus, Approaches to singular analysis (Berlin, 1999) Oper. Theory Adv. Appl., vol. 125, Birkhäuser, Basel, 2001, pp. 30–84. MR 1827170
- Taoufik Hmidi and Sahbi Keraani, Blowup theory for the critical nonlinear Schrödinger equations revisited, Int. Math. Res. Not. 46 (2005), 2815–2828. MR 2180464, DOI https://doi.org/10.1155/IMRN.2005.2815
- Justin Holmer, The initial-boundary value problem for the Korteweg-de Vries equation, Comm. Partial Differential Equations 31 (2006), no. 7-9, 1151–1190. MR 2254610, DOI https://doi.org/10.1080/03605300600718503
- John K. Hunter, Asymptotic equations for nonlinear hyperbolic waves, Surveys in applied mathematics, Vol. 2, Surveys Appl. Math., vol. 2, Plenum, New York, 1995, pp. 167–276. MR 1387617, DOI https://doi.org/10.1007/978-1-4615-1991-1_3
- J. K. Hunter, Private communication, 2016.
- John K. Hunter and Ralph Saxton, Dynamics of director fields, SIAM J. Appl. Math. 51 (1991), no. 6, 1498–1521. MR 1135995, DOI https://doi.org/10.1137/0151075
- J. Krieger and W. Schlag, Stable manifolds for all monic supercritical focusing nonlinear Schrödinger equations in one dimension, J. Amer. Math. Soc. 19 (2006), no. 4, 815–920. MR 2219305, DOI https://doi.org/10.1090/S0894-0347-06-00524-8
- J.-G. Liu, J. Lu, D. Margetis, and J. L. Marzuola, Asymmetry in crystal facet dynamics of homoepitaxy by a continuum model, arXiv preprint arXiv:1704.01554, 2017.
- Andrew Majda, Rodolfo Rosales, and Maria Schonbek, A canonical system of integrodifferential equations arising in resonant nonlinear acoustics, Stud. Appl. Math. 79 (1988), no. 3, 205–262. MR 975485, DOI https://doi.org/10.1002/sapm1988793205
- Rafe Mazzeo, Elliptic theory of differential edge operators. I, Comm. Partial Differential Equations 16 (1991), no. 10, 1615–1664. MR 1133743, DOI https://doi.org/10.1080/03605309108820815
- Richard B. Melrose, Pseudodifferential operators, corners and singular limits, ICM-90, Mathematical Society of Japan, Tokyo; distributed outside Asia by the American Mathematical Society, Providence, RI, 1990. A plenary address presented at the International Congress of Mathematicians held in Kyoto, August 1990. MR 1127161
- Richard B. Melrose, The Atiyah-Patodi-Singer index theorem, Research Notes in Mathematics, vol. 4, A K Peters, Ltd., Wellesley, MA, 1993. MR 1348401
- R. B. Melrose, Differential analysis on manifolds with corners, 1996.
- Bogdan Mihaila, Andres Cardenas, Fred Cooper, and Avadh Saxena, Stability and dynamical properties of Cooper-Shepard-Sodano compactons, Phys. Rev. E (3) 82 (2010), no. 6, 066702, 11. MR 2787498, DOI https://doi.org/10.1103/PhysRevE.82.066702
- Bela v. Sz. Nagy, Über Integralungleichungen zwischen einer Funktion und ihrer Ableitung, Acta Univ. Szeged. Sect. Sci. Math. 10 (1941), 64–74 (German). MR 4277
- V. Nesterenko, Dynamics of heterogeneous materials, 2001.
- Igor Rodnianski, Wilhelm Schlag, and Avraham Soffer, Dispersive analysis of charge transfer models, Comm. Pure Appl. Math. 58 (2005), no. 2, 149–216. MR 2094850, DOI https://doi.org/10.1002/cpa.20066
- Philip Rosenau, Nonlinear dispersion and compact structures, Phys. Rev. Lett. 73 (1994), no. 13, 1737–1741. MR 1294558, DOI https://doi.org/10.1103/PhysRevLett.73.1737
- Philip Rosenau, What is$\dots $a compacton?, Notices Amer. Math. Soc. 52 (2005), no. 7, 738–739. MR 2159688
- P. Rosenau, On a model equation of traveling and stationary compactons, Physics Letters A, 356(1):44–50, 2006.
- Philip Rosenau, Compact breathers in a quasi-linear Klein-Gordon equation, Phys. Lett. A 374 (2010), no. 15-16, 1663–1667. MR 2601818, DOI https://doi.org/10.1016/j.physleta.2010.01.065
- P. Rosenau and J. M. Hyman, Compactons: solitons with finite wavelength, Physical Review Letters, 70(5):564, 1993.
- Philip Rosenau and Steven Schochet, Compact and almost compact breathers: a bridge between an anharmonic lattice and its continuum limit, Chaos 15 (2005), no. 1, 015111, 18. MR 2133462, DOI https://doi.org/10.1063/1.1852292
- W. Schlag, Dispersive estimates for Schrödinger operators: a survey, Mathematical aspects of nonlinear dispersive equations, Ann. of Math. Stud., vol. 163, Princeton Univ. Press, Princeton, NJ, 2007, pp. 255–285. MR 2333215
- W. Schlag, Dispersive estimates for Schrödinger operators: a survey, Mathematical aspects of nonlinear dispersive equations, Ann. of Math. Stud., vol. 163, Princeton Univ. Press, Princeton, NJ, 2007, pp. 255–285. MR 2333215
- W. Schlag, Stable manifolds for an orbitally unstable nonlinear Schrödinger equation, Ann. of Math. (2) 169 (2009), no. 1, 139–227. MR 2480603, DOI https://doi.org/10.4007/annals.2009.169.139
- G. Simpson, M. Spiegelman, and M. I. Weinstein, Degenerate dispersive equations arising in the study of magma dynamics, Nonlinearity 20 (2007), no. 1, 21–49. MR 2285103, DOI https://doi.org/10.1088/0951-7715/20/1/003
- Catherine Sulem and Pierre-Louis Sulem, The nonlinear Schrödinger equation, Applied Mathematical Sciences, vol. 139, Springer-Verlag, New York, 1999. Self-focusing and wave collapse. MR 1696311
- Terence Tao, Nonlinear dispersive equations, CBMS Regional Conference Series in Mathematics, vol. 106, Published for the Conference Board of the Mathematical Sciences, Washington, DC; by the American Mathematical Society, Providence, RI, 2006. Local and global analysis. MR 2233925
- Gerald Teschl, Ordinary differential equations and dynamical systems, Graduate Studies in Mathematics, vol. 140, American Mathematical Society, Providence, RI, 2012. MR 2961944
- Gerald Teschl, Mathematical methods in quantum mechanics, 2nd ed., Graduate Studies in Mathematics, vol. 157, American Mathematical Society, Providence, RI, 2014. With applications to Schrödinger operators. MR 3243083
- Joachim Weidmann, Spectral theory of ordinary differential operators, Lecture Notes in Mathematics, vol. 1258, Springer-Verlag, Berlin, 1987. MR 923320
- Michael I. Weinstein, Nonlinear Schrödinger equations and sharp interpolation estimates, Comm. Math. Phys. 87 (1982/83), no. 4, 567–576. MR 691044
- Lijun Zhang and Li-Qun Chen, Envelope compacton and solitary pattern solutions of a generalized nonlinear Schrödinger equation, Nonlinear Anal. 70 (2009), no. 1, 492–496. MR 2468255, DOI https://doi.org/10.1016/j.na.2007.12.020
- Alon Zilburg and Philip Rosenau, On Hamiltonian formulations of the $\mathcal {C}_1(m,a,b)$ equations, Phys. Lett. A 381 (2017), no. 18, 1557–1562. MR 3628993, DOI https://doi.org/10.1016/j.physleta.2017.03.009
References
- David M. Ambrose, Gideon Simpson, J. Douglas Wright, and Dennis G. Yang, Ill-posedness of degenerate dispersive equations, Nonlinearity 25 (2012), no. 9, 2655–2680. MR 2967120, DOI https://doi.org/10.1088/0951-7715/25/9/2655
- H. Berestycki and P.-L. Lions, Nonlinear scalar field equations. I. Existence of a ground state, Arch. Rational Mech. Anal. 82 (1983), no. 4, 313–345. MR 695535, DOI https://doi.org/10.1007/BF00250555
- F. Betancourt, R. Bürger, K. H. Karlsen, and E. M. Tory, On nonlocal conservation laws modelling sedimentation, Nonlinearity 24 (2011), no. 3, 855–885. MR 2772627, DOI https://doi.org/10.1088/0951-7715/24/3/008
- Joseph Biello and John K. Hunter, Nonlinear Hamiltonian waves with constant frequency and surface waves on vorticity discontinuities, Comm. Pure Appl. Math. 63 (2010), no. 3, 303–336. MR 2599457, DOI https://doi.org/10.1002/cpa.20304
- Jerry L. Bona, Shu Ming Sun, and Bing-Yu Zhang, A nonhomogeneous boundary-value problem for the Korteweg-de Vries equation posed on a finite domain, Comm. Partial Differential Equations 28 (2003), no. 7-8, 1391–1436. MR 1998942, DOI https://doi.org/10.1081/PDE-120024373
- M. Burak Erdoğan and Wilhelm Schlag, Dispersive estimates for Schrödinger operators in the presence of a resonance and/or an eigenvalue at zero energy in dimension three. II, J. Anal. Math. 99 (2006), 199–248. MR 2279551, DOI https://doi.org/10.1007/BF02789446
- Miguel Andres Caicedo and Bing-Yu Zhang, Well-posedness of a nonlinear boundary value problem for the Korteweg–de Vries equation on a bounded domain, J. Math. Anal. Appl. 448 (2017), no. 2, 797–814. MR 3582261, DOI https://doi.org/10.1016/j.jmaa.2016.11.032
- Roberto Camassa and Darryl D. Holm, An integrable shallow water equation with peaked solitons, Phys. Rev. Lett. 71 (1993), no. 11, 1661–1664. MR 1234453, DOI https://doi.org/10.1103/PhysRevLett.71.1661
- Hans Christianson, Jeremy Marzuola, Jason Metcalfe, and Michael Taylor, Nonlinear bound states on weakly homogeneous spaces, Comm. Partial Differential Equations 39 (2014), no. 1, 34–97. MR 3169779, DOI https://doi.org/10.1080/03605302.2013.845044
- James E. Colliander, Jeremy L. Marzuola, Tadahiro Oh, and Gideon Simpson, Behavior of a model dynamical system with applications to weak turbulence, Exp. Math. 22 (2013), no. 3, 250–264. MR 3171091, DOI https://doi.org/10.1080/10586458.2013.793110
- Fred Cooper, Harvey Shepard, and Pasquale Sodano, Solitary waves in a class of generalized Korteweg-de Vries equations, Phys. Rev. E (3) 48 (1993), no. 5, 4027–4032. MR 1376975, DOI https://doi.org/10.1103/PhysRevE.48.4027
- Hui-Hui Dai and Yi Huo, Solitary shock waves and other travelling waves in a general compressible hyperelastic rod, R. Soc. Lond. Proc. Ser. A Math. Phys. Eng. Sci. 456 (2000), no. 1994, 331–363. MR 1811323, DOI https://doi.org/10.1098/rspa.2000.0520
- G. A. El, M. A. Hoefer, and M. Shearer, Dispersive and diffusive-dispersive shock waves for nonconvex conservation laws, SIAM Rev. 59 (2017), no. 1, 3–61. MR 3605824, DOI https://doi.org/10.1137/15M1015650
- Daniel Grieser, Basics of the $b$-calculus, Approaches to singular analysis (Berlin, 1999) Oper. Theory Adv. Appl., vol. 125, Birkhäuser, Basel, 2001, pp. 30–84. MR 1827170
- Taoufik Hmidi and Sahbi Keraani, Blowup theory for the critical nonlinear Schrödinger equations revisited, Int. Math. Res. Not. 46 (2005), 2815–2828. MR 2180464, DOI https://doi.org/10.1155/IMRN.2005.2815
- Justin Holmer, The initial-boundary value problem for the Korteweg-de Vries equation, Comm. Partial Differential Equations 31 (2006), no. 7-9, 1151–1190. MR 2254610, DOI https://doi.org/10.1080/03605300600718503
- John K. Hunter, Asymptotic equations for nonlinear hyperbolic waves, Surveys in applied mathematics, Vol. 2, Surveys Appl. Math., vol. 2, Plenum, New York, 1995, pp. 167–276. MR 1387617, DOI https://doi.org/10.1007/978-1-4615-1991-1_3
- J. K. Hunter, Private communication, 2016.
- John K. Hunter and Ralph Saxton, Dynamics of director fields, SIAM J. Appl. Math. 51 (1991), no. 6, 1498–1521. MR 1135995, DOI https://doi.org/10.1137/0151075
- J. Krieger and W. Schlag, Stable manifolds for all monic supercritical focusing nonlinear Schrödinger equations in one dimension, J. Amer. Math. Soc. 19 (2006), no. 4, 815–920. MR 2219305, DOI https://doi.org/10.1090/S0894-0347-06-00524-8
- J.-G. Liu, J. Lu, D. Margetis, and J. L. Marzuola, Asymmetry in crystal facet dynamics of homoepitaxy by a continuum model, arXiv preprint arXiv:1704.01554, 2017.
- Andrew Majda, Rodolfo Rosales, and Maria Schonbek, A canonical system of integrodifferential equations arising in resonant nonlinear acoustics, Stud. Appl. Math. 79 (1988), no. 3, 205–262. MR 975485, DOI https://doi.org/10.1002/sapm1988793205
- Rafe Mazzeo, Elliptic theory of differential edge operators. I, Comm. Partial Differential Equations 16 (1991), no. 10, 1615–1664. MR 1133743, DOI https://doi.org/10.1080/03605309108820815
- Richard B. Melrose, Pseudodifferential operators, corners and singular limits, with a plenary address presented at the International Congress of Mathematicians held in Kyoto, August 1990, ICM-90, Mathematical Society of Japan, Tokyo; distributed outside Asia by the American Mathematical Society, Providence, RI, 1990. MR 1127161
- Richard B. Melrose, The Atiyah-Patodi-Singer index theorem, Research Notes in Mathematics, vol. 4, A K Peters, Ltd., Wellesley, MA, 1993. MR 1348401
- R. B. Melrose, Differential analysis on manifolds with corners, 1996.
- Bogdan Mihaila, Andres Cardenas, Fred Cooper, and Avadh Saxena, Stability and dynamical properties of Cooper-Shepard-Sodano compactons, Phys. Rev. E (3) 82 (2010), no. 6, 066702, 11. MR 2787498, DOI https://doi.org/10.1103/PhysRevE.82.066702
- Bela v. Sz. Nagy, Über Integralungleichungen zwischen einer Funktion und ihrer Ableitung, Acta Univ. Szeged. Sect. Sci. Math. 10 (1941), 64–74 (German). MR 0004277
- V. Nesterenko, Dynamics of heterogeneous materials, 2001.
- Igor Rodnianski, Wilhelm Schlag, and Avraham Soffer, Dispersive analysis of charge transfer models, Comm. Pure Appl. Math. 58 (2005), no. 2, 149–216. MR 2094850, DOI https://doi.org/10.1002/cpa.20066
- Philip Rosenau, Nonlinear dispersion and compact structures, Phys. Rev. Lett. 73 (1994), no. 13, 1737–1741. MR 1294558, DOI https://doi.org/10.1103/PhysRevLett.73.1737
- Philip Rosenau, What is$\dots$a compacton?, Notices Amer. Math. Soc. 52 (2005), no. 7, 738–739. MR 2159688
- P. Rosenau, On a model equation of traveling and stationary compactons, Physics Letters A, 356(1):44–50, 2006.
- Philip Rosenau, Compact breathers in a quasi-linear Klein-Gordon equation, Phys. Lett. A 374 (2010), no. 15-16, 1663–1667. MR 2601818, DOI https://doi.org/10.1016/j.physleta.2010.01.065
- P. Rosenau and J. M. Hyman, Compactons: solitons with finite wavelength, Physical Review Letters, 70(5):564, 1993.
- Philip Rosenau and Steven Schochet, Compact and almost compact breathers: a bridge between an anharmonic lattice and its continuum limit, Chaos 15 (2005), no. 1, 015111, 18. MR 2133462, DOI https://doi.org/10.1063/1.1852292
- W. Schlag, Dispersive estimates for Schrödinger operators: a survey, Mathematical aspects of nonlinear dispersive equations, Ann. of Math. Stud., vol. 163, Princeton Univ. Press, Princeton, NJ, 2007, pp. 255–285. MR 2333215
- W. Schlag, Dispersive estimates for Schrödinger operators: a survey, Mathematical aspects of nonlinear dispersive equations, Ann. of Math. Stud., vol. 163, Princeton Univ. Press, Princeton, NJ, 2007, pp. 255–285. MR 2333215
- W. Schlag, Stable manifolds for an orbitally unstable nonlinear Schrödinger equation, Ann. of Math. (2) 169 (2009), no. 1, 139–227. MR 2480603, DOI https://doi.org/10.4007/annals.2009.169.139
- G. Simpson, M. Spiegelman, and M. I. Weinstein, Degenerate dispersive equations arising in the study of magma dynamics, Nonlinearity 20 (2007), no. 1, 21–49. MR 2285103, DOI https://doi.org/10.1088/0951-7715/20/1/003
- Catherine Sulem and Pierre-Louis Sulem, The nonlinear Schrödinger equation, Applied Mathematical Sciences, vol. 139, Springer-Verlag, New York, 1999. Self-focusing and wave collapse. MR 1696311
- Terence Tao, Nonlinear dispersive equations, with Local and global analysis, CBMS Regional Conference Series in Mathematics, vol. 106, Published for the Conference Board of the Mathematical Sciences, Washington, DC; by the American Mathematical Society, Providence, RI, 2006. MR 2233925
- Gerald Teschl, Ordinary differential equations and dynamical systems, Graduate Studies in Mathematics, vol. 140, American Mathematical Society, Providence, RI, 2012. MR 2961944
- Gerald Teschl, Mathematical methods in quantum mechanics, with with applications to Schrödinger operators, 2nd ed., Graduate Studies in Mathematics, vol. 157, American Mathematical Society, Providence, RI, 2014. MR 3243083
- Joachim Weidmann, Spectral theory of ordinary differential operators, Lecture Notes in Mathematics, vol. 1258, Springer-Verlag, Berlin, 1987. MR 923320
- Michael I. Weinstein, Nonlinear Schrödinger equations and sharp interpolation estimates, Comm. Math. Phys. 87 (1982/83), no. 4, 567–576. MR 691044
- Lijun Zhang and Li-Qun Chen, Envelope compacton and solitary pattern solutions of a generalized nonlinear Schrödinger equation, Nonlinear Anal. 70 (2009), no. 1, 492–496. MR 2468255, DOI https://doi.org/10.1016/j.na.2007.12.020
- Alon Zilburg and Philip Rosenau, On Hamiltonian formulations of the $\mathcal {C}_1(m,a,b)$ equations, Phys. Lett. A 381 (2017), no. 18, 1557–1562. MR 3628993, DOI https://doi.org/10.1016/j.physleta.2017.03.009
Similar Articles
Retrieve articles in Quarterly of Applied Mathematics
with MSC (2010):
35Q53,
35Q55
Retrieve articles in all journals
with MSC (2010):
35Q53,
35Q55
Additional Information
Pierre Germain
Affiliation:
Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, New York 10012
MR Author ID:
758713
Email:
pgermain@cims.nyu.edu
Benjamin Harrop-Griffiths
Affiliation:
Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, New York 10012
MR Author ID:
1086344
ORCID:
0000-0002-0215-7613
Email:
benjamin.harrop-griffiths@cims.nyu.edu
Jeremy L. Marzuola
Affiliation:
Department of Mathematics, University of North Carolina, Phillips Hall, Chapel Hill, North Carolina 27599
MR Author ID:
787291
Email:
marzuola@math.unc.edu
Received by editor(s):
August 16, 2018
Received by editor(s) in revised form:
January 29, 2019
Published electronically:
April 17, 2019
Additional Notes:
The first author was supported by the NSF grant DMS-15010.
The second author was supported by a Junior Fellow award from the Simons Foundation.
The third author was supported in part by U.S. NSF Grants DMS–1312874 and DMS-1352353.
Article copyright:
© Copyright 2019
Brown University