×

Multi-pulse edge-localized states on quantum graphs. (English) Zbl 1477.35242

Summary: We construct the edge-localized stationary states of the nonlinear Schrödinger equation on a general quantum graph in the limit of large mass. Compared to the previous works, we include arbitrary multi-pulse positive states which approach asymptotically a composition of \(N\) solitons, each sitting on a bounded (pendant, looping, or internal) edge. We give sufficient conditions on the edge lengths of the graph under which such states exist in the limit of large mass. In addition, we compute the precise Morse index (the number of negative eigenvalues in the corresponding linearized operator) for these multi-pulse states. If \(N\) solitons of the edge-localized state reside on the pendant and looping edges, we prove that the Morse index is exactly \(N\). The technical novelty of this work is achieved by avoiding elliptic functions (and related exponentially small scalings) and closing the existence arguments in terms of the Dirichlet-to-Neumann maps for relevant parts of the given graph. We illustrate the general results with three examples of the flower, dumbbell, and single-interval graphs.

MSC:

35Q55 NLS equations (nonlinear Schrödinger equations)
35Q41 Time-dependent Schrödinger equations and Dirac equations
35C08 Soliton solutions
35P99 Spectral theory and eigenvalue problems for partial differential equations
81Q10 Selfadjoint operator theory in quantum theory, including spectral analysis

Software:

QGLAB

References:

[1] Adami, R.; Serra, E.; Tilli, P., NLS ground states on graphs, Calc. Var., 54, 743-761 (2015) · Zbl 1330.35484 · doi:10.1007/s00526-014-0804-z
[2] Adami, R.; Serra, E.; Tilli, P., Threshold phenomena and existence results for NLS ground states on graphs, J. Funct. Anal., 271, 201-223 (2016) · Zbl 1338.35448 · doi:10.1016/j.jfa.2016.04.004
[3] Adami, R.; Serra, E.; Tilli, P., Negative energy ground states for the \(L^2\)-critical NLSE on metric graphs, Commun. Math. Phys., 352, 387-406 (2017) · Zbl 1372.35319 · doi:10.1007/s00220-016-2797-2
[4] Adami, R.; Serra, E.; Tilli, P., Multiple positive bound states for the subcritical NLS equation on metric graphs, Calc. Var., 58, 5 (2019) · Zbl 1405.35236 · doi:10.1007/s00526-018-1461-4
[5] Berkolaiko, G., Kuchment, P.: Introduction to Quantum Graphs (Mathematical Surveys and Monographs, vol 186. American Mathematical Society, Providence, RI (2013) · Zbl 1318.81005
[6] Berkolaiko, G., Marzuola, J., Pelinovsky, D.E.: Edge-localized states on quantum graphs in the limit of large mass. Ann. de l’Inst. Henri Poincaré C Anal. Non linéaire 38, 1295-1335 (2021) · Zbl 1477.35230
[7] Berkolaiko, G.; Kennedy, JB; Kurasov, P.; Mugnolo, D., Surgery principles for the spectral analysis of quantum graphs, Trans. AMS, 372, 5153-5197 (2019) · Zbl 1451.34029 · doi:10.1090/tran/7864
[8] Cacciapuoti, C., Finco, D., Noja, D.: Topology induced bifurcations for the NLS on the tadpole graph. Phys. Rev. E 91, 013206 (2015) · Zbl 1373.35284
[9] Dovetta, S., Serra, E., Tilli, P.: Uniqueness and non-uniqueness of prescribed mass NLS ground states on metric graphs, Adv. Math. 374 (2020), 107352 (41 pages) · Zbl 1511.34037
[10] Dovetta, S.; Ghimenti, M.; Micheletti, AM; Pistoia, A., Peaked and low action solutions of NLS equations on graphs with terminal edges, SIAM J. Math. Anal., 52, 2874-2894 (2020) · Zbl 1454.35336 · doi:10.1137/19M127447X
[11] Exner, P.; Kovarik, H., Quantum Waveguides. Theoretical and Mathematical Physics (2015), Cham: Springer, Cham · Zbl 1314.81001 · doi:10.1007/978-3-319-18576-7
[12] Garijo, A.; Villadelprat, J., Algebraic and analytical tools for the study of the period function, J. Differ. Eqs., 257, 2464-2484 (2014) · Zbl 1305.34050 · doi:10.1016/j.jde.2014.05.044
[13] Goodman, R.H., Conte, G., Marzuola, J.L.: Quantum Graphs Package, version 0.96 (2021), doi:10.5281/zenodo.4898112
[14] Goodman, RH, NLS bifurcations on the bowtie combinatorial graph and the dumbbell metric graph, Discrete Contin. Dyn. Syst., 39, 4, 2203-2232 (2019) · Zbl 1410.35266 · doi:10.3934/dcds.2019093
[15] Grillakis, M., Linearized instability for nonlinear Schrödinger and Klein-Gordon equations, Commun. Pure Appl. Math., 41, 747-774 (1988) · Zbl 0632.70015 · doi:10.1002/cpa.3160410602
[16] Grillakis, M.; Shatah, J.; Strauss, W., Stability theory of solitary waves in the presence of symmetry I, J. Funct. Anal., 74, 160-197 (1987) · Zbl 0656.35122 · doi:10.1016/0022-1236(87)90044-9
[17] Kairzhan, A.; Marangell, R.; Pelinovsky, DE; Xiao, K., Standing waves on a flower graph, J. Differ. Eqs., 271, 719-763 (2021) · Zbl 1454.35406 · doi:10.1016/j.jde.2020.09.010
[18] Kato, T.: Perturbation Theory for Linear Operators. Classics in Mathematics. Springer, Berlin (1995) · Zbl 0836.47009
[19] Kurata, K., Shibata, M.: Least energy solutions to semi-linear elliptic problems on metric graphs. J. Math. Anal. Appl. 491 124297 (22 pages) (2020) · Zbl 1448.35250
[20] Latushkin, Y.; Sukhtaiev, S., An index theorem for Schrödinger operators on metric graphs, Contemp. Math., 741, 105-119 (2020) · Zbl 1457.58014 · doi:10.1090/conm/741/14922
[21] Marzuola, JL; Pelinovsky, DE, Ground state on the dumbbell graph, Appl. Math. Res. Express. AMRX, 1, 98-145 (2016) · Zbl 1345.35105 · doi:10.1093/amrx/abv011
[22] Noja, D., Pelinovsky, D.E. (eds.): Symmetries of Nonlinear PDEs on Metric Graphs and Branched Networks. MDPI, Basel (2019)
[23] Noja, D., Pelinovsky, D.E.: Standing waves of the quintic NLS equation on the tadpole graph. Calc. Var. Partial Differ. Equ. 59 (2020) 173 (31 pages) · Zbl 1448.35474
[24] Noja, D.: Nonlinear Schrödinger equation on graphs: recent results and open problems, Philos. Trans. R. Soc. A, 372, 20130002 (20 pages) (2014) · Zbl 1322.35130
[25] Noja, D.; Pelinovsky, D.; Shaikhova, G., Bifurcations and stability of standing waves in the nonlinear Schrödinger equation on the tadpole graph, Nonlinearity, 28, 2343-2378 (2015) · Zbl 1328.35216 · doi:10.1088/0951-7715/28/7/2343
[26] Shatah, J., Strauss, W.: Spectral conditions for instability, Nonlinear PDE’s, dynamics and continuum physics (South Hadley, MA, 1998), Contemp. Math. Am. Math. Soc., Providence, RI, 255, 189-198 (2000) · Zbl 0960.47033
[27] Teschl, G., Ordinary Differential Equations and Dynamical Systems, Graduate Studies in Mathematics 140 (2012), Providence: AMS, Providence · Zbl 1263.34002 · doi:10.1090/gsm/140
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.