• Aucun résultat trouvé

Higher order Peregrine breathers and multi-rogue waves solutions of the NLS equation

N/A
N/A
Protected

Academic year: 2021

Partager "Higher order Peregrine breathers and multi-rogue waves solutions of the NLS equation"

Copied!
26
0
0

Texte intégral

(1)

HAL Id: hal-00589556

https://hal.archives-ouvertes.fr/hal-00589556v3

Preprint submitted on 16 Sep 2012

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci-

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents

Higher order Peregrine breathers and multi-rogue waves solutions of the NLS equation

Pierre Gaillard

To cite this version:

Pierre Gaillard. Higher order Peregrine breathers and multi-rogue waves solutions of the NLS equation.

2012. �hal-00589556v3�

(2)

Higher order Peregrine breathers and multi-rogue waves solutions of

the NLS equation.

+Pierre Gaillard, + Universit´e de Bourgogne, Dijon, France : e-mail: [email protected],

April 25, 2011

Abstract

This work is a continuation of a recent paper in which we have constructed a multi-parametric family of solutions of the focusing NLS equation given in terms of Wronskians determinants of order 2N com- posed of elementary trigonometric functions. When we perform a special passage to the limit when all the periods tend to infinity, we get a family of quasi-rational solutions. Here we construct Peregrine breathers of ordersN = 4,5,and the multi-rogue waves corresponding the 10 or 15 peak formation in frame of the NLS model first explained by Matveev et al. in 2010. In the cases N = 4,5 we get comfortable formulas to study the deformation of higher Peregrine breather of or- der 4 to the 10 rogue-waves or order 5 to the 15 rogue-waves solution via variation of the free parameters of our construction.

1 Introduction

The nonlinear Schr¨odinger equation (NLS) was first derived by Zakharov [16]

in 1968. The solutions were first given by Zakharov and Schabat. The case of periodic and almost periodic algebro-geometric solutions to the focusing NLS

(3)

Akhmediev and Kulagin obtained the two-phase almost periodic solution to the NLS equation and obtained the first higher order analogue of the Pere- grine breather[3]. Other families of higher order were constructed in a series of articles by Akhmediev et al. [1, 2] using Darboux transformations. In 2010 it has been shown in [6] that rational solutions of NLS equation can be written as a quotient of two wronskians and it has been recovered as partic- ular case, Akhmediev’s quasi-rational solutions of NLS equation.

In this paper, we extend a result [10] giving a new representation of the solutions of the NLS equation in terms of a ratio of two wronskians deter- minants of even order 2N composed of elementary functions; the related solutions of NLS are called of order N. When we perform the passage to the limit when some parameter tends to 0, we got families of multi-rogue wave solutions of the focusing NLS equation depending on a certain number of parameters. It allows to recognize the famous Peregrine’s breather [14] and also higher order Peregrine’s breathers constructed by Akhmediev [1, 4].

We treat in the following the cases of order N = 4 and N = 5. We get for an arbitrary choice of the parameters the shape of Akhmediev’s breathers;

we can also get, for particular parameters, the apparition of peaks of similar amplitude for the modulus of the solution v in the (x;y) coordinates.

2 Expression of solutions of NLS equation in terms of Wronskian determinant and quasi- rational limit

2.1 Solutions of NLS equation in terms of Wronskian determinant

We briefly recall results obtained in [10]. We consider the focusing NLS equation

ivt+vxx+ 2|v|2v = 0. (1)

From [10], the solution of the NLS equation can be written in the form

(4)

In (2), the matrix Ar = (aνµ)1ν,µ2N is defined by aνµ = (−1)ǫν Y

λ6

γλ+γν γλ γµ

exp(iκνxνt+xr,ν +eν). (3) The terms ǫν are defined by :

ǫν = 0, 1ν N

ǫν = 1, N + 1ν 2N. (4)

We consider the following functions

φrν(y) = sin(κνx/2 +νtixr,ν/2 +γνyieν), 1ν N,

φrν(y) = cos(κνx/2 +νtixr,ν/2 +γνyieν), N + 1 ν2N. (5) We use the following notations :

Θν =κνx/2 +νtixr,ν/2 +γνyieν, 1ν 2N.

Wr(y) =W1, . . . , φ2N) is the wronskian

Wr(y) = det[(∂yµ1φν)ν, µ[1,...,2N]]. (6) We consider the matrix Dr = (dνµ)ν, µ∈[1,...,2N] defined by

dνµ= (−1)ǫνQ

λ6

γλν

γλγµ

exp(iκνxνt+xr,νieν), 1ν 2N, 1µ2N,

with

xr,ν = (r1) lnγν i γν +i.

Then we get the following link between Fredohlm and Wronskian determi- nants [9]

Theorem 2.1

det(I+Dr) =kr(0)×Wr1, . . . , φ2N)(0), (7)

(5)

It can be deduced the following result : Theorem 2.2 The function v defined by

v(x, t) = W3(0)

W1(0)exp(2itiϕ). (8)

is solution of the NLS equation (1)

ivt+vxx+ 2|v|2v = 0.

2.2 Quasi-rational solutions of NLS equation

In the following, we take the limit when the parametersλj 1 for 1j N and λj → −1 for N+ 1 j 2N.

For simplicity, we denote dj the term cj2.

We consider the parameter λj written in the form

λj = 12d2j, 1j N. (9) When ǫ goes to 0, we realize limited expansions at order p, for 1 j N, of the terms

κj = 4djǫ(1ǫ2d2j)1/2,δj = 4djǫ(12d2j)(1ǫ2d2j)1/2, γj =djǫ(1ǫ2d2j)−1/2, xr,j = (r1) ln1+iǫd1iǫdj(1ǫ2d2j)−1/2

j(1ǫ2d2j)−1/2,

κN+j = 4djǫ(1ǫ2d2j)1/2, δN+j =−4djǫ(12d2j)(1ǫ2d2j)1/2, γN+j = 1/(djǫ)(1ǫ2d2j)1/2, xr,N+j = (r1) ln11+iǫdiǫdj(1ǫ2d2j)−1/2

j(1ǫ2d2j)−1/2. The parameters aj and bj, for 1N are chosen in the form

aj = ˜ajǫM1, bj = ˜bjǫM1, 1j N, M = 2N. (10) We have the central result given in [10] :

Theorem 2.3 With the parameters λj defined by (9), aj and bj chosen as in (10), for 1j N, the functionv defined by

v(x, t) = exp(2itiϕ) lim

ǫ→0

W3(0)

W1(0), (11)

is a quasi-rational solution of the NLS equation (1) ivt+vxx+ 2|v|2v = 0,

(6)

3 Quasi-rational solutions of order N

To get solutions of NLS equation written in the context of fiber optics iux+1

2utt+u|u|2 = 0, (12)

from these of (1), we can make the following changes of variables tX/2

xT. (13)

In the following, because of the complexity of the expression, we give all the solutions in the case where the parameters dj are equal to j and all the parameters aj and bj are equal to 0.

The solution of NLS equation can be written in the form vN(x, t) = n(x, t)

d(x, t) exp(2itiϕ) = (1αN

GN(2x,4t) +iHN(2x,4t) QN(2x,4t) )e2it with

GN(X, T) = PN(N+1)

k=0 gk(T)Xk HN(X, T) = PN(N+1)

k=0 hk(T)Xk QN(X, T) = PN(N+1)

k=0 qk(T)Xk

3.1 Case N=4

In the case of order N = 4, we make an expansion at order 7. Taking the limit when ǫ0, the solution of NLS equation (12) takes the form

v(x, t) = n(x, t)

d(x, t)exp(2itiϕ).

(7)

α4= 4, g20= 0, g19= 0, g18= 10, g17= 0, g16= 270T2+ 270, g15= 0, g14= 1800T4

−3600T2+ 9000, g13= 0, g12= 5880T654600T412600T2+ 189000, g11= 0, g10= 11340T8176400T6+ 189000T4378000T21077300, g9= 0,

g8= 13860T10207900T8+ 2356200T6+ 1701000T456983500T24819500, g7= 0, g6= 10920T1218480T10+ 6967800T8+ 56095200T6342657000T4 +198450000T211907000, g5= 0 g4= 5400T14+ 163800T12+ 9034200T10 +107919000T8615195000T6+ 178605000T4+ 654885000T2+ 178605000, g3= 0, g2= 1530T16+ 133200T14+ 5506200T12116802000T101731334500T8

+2532222000T6893025000T4+ 4643730000)T2+ 223256250, g1= 0, g0= 190T18+ 33150T16+ 1294200T14+ 3288600T12+ 48629700T10

−2015401500T81845585000T6+ 14586075000)T4+ 2098608750T244651250,

h20= 0, h19= 0, h18= 10T, h17= 0, h16= 90T3270T, h15= 0, h14= 360T5

−6000T35400T, h13= 0, h12= 840T729400T5+ 12600T3138600T, h11= 0, h10= 1260T965520T7+ 259560T5529200T31984500T, h9= 0,

h8= 1260T1177700T9+ 718200T75329800T56142500T3+ 29767500T, h7= 0, h6= 840T1348720T11+ 718200T9+ 2973600T772765000T5 +436590000T3+ 146853000T,h5= 0, h4= 360T1512600T13+ 138600T11

−5859000T9328293000T7+ 1075599000T5+ 773955000T3+ 535815000T, h3= 0, h2= 90T17+ 1200T15189000T1340143600T11

−307786500T9+ 2085426000T74465125000T5+ 4405590000T31205583750T, h1= 0, h0= 10T19+ 930T1786040T157018200T1348100500T11542902500T9

+6039117000T7+ 12942909000T5+ 937676250T3, q20= 1, q19= 0, q18= 10T2+ 10, q17= 0, q16= 45T4270T2+ 405, q15= 0,

q14= 120T61800T4+ 1800T2+ 16200, q13= 0, q12= 210T84200T6+ 6300T4 +113400T2+ 425250, q11= 0, q10= 252T103780T8+ 63000T6

+718200T4+ 3005100T2+ 1644300, q9= 0, q8= 210T12+ 1260T10 +255150T8567000T6+ 23388750T431468500T2+ 17435250, q7= 0, q6= 120T14+ 5880T12+ 476280T10+ 16443000T8+ 162729000T6

−154791000T4+ 130977000T2+ 130977000, q5= 0, q4= 45T16+ 5400T14 +459900T12+ 19845000T10+ 153798750T8+ 702513000T689302500T4 +1250235000T2+ 111628125,q3= 0, q2= 10T18

+2250T16+ 225000T14+ 4422600T1299508500T10224248500T8 +9704205000T6+ 15181425000T41920003750T2+ 223256250, q1= 0, q0=T20+ 370T18+ 44325T16+ 2208600T14+ 62795250T12+ 693384300T10 +6641129250T8+ 4346055000T6+ 14042818125)T4+ 2902331250T2+ 22325625

The plot of the modulus of v in the (x, t) coordinates gives :

(8)

Figure 1: Solution of NLS, N=4a.

If we choose a1 = 1, a2 = 1, a3 = 1, a4 = 1, b1 = 1, b2 = 1, b3 = 1, b4 = 1, we have the same type of analytical expression for the modulus ofv;

we don’t reproduce here.

We only give shape of the modulus of v in the (x, t) coordinates :

(9)

Figure 2: Solution of NLS, N=4b.

If we choosea1 = 0,a2 = 0, a3 = 0, a4 = 0, b1 = 1000000, b2 = 1000000, b3 = 1000000, b4 = 1000000, the shape of the modulus of v in the (x, t) coordinates is given by :

(10)

Figure 3: Solution of NLS, N=4c.

In these three plots, we can see the deformation of the initial Akhmediev’s breather to multi-rogue waves, by choosing different types of the parameters among the 8 given by our formulation.

3.2 Case N=5

In the case N = 5, we realize an expansion at order 9 in ǫ. From (11), we get solutions of NLS equation. Taking the limit when ǫ0, the solution of NLS equation takes the form

v(x, t) = n(x, t)

d(x, t)exp(2itiϕ).

(11)

α5= 60, g30= 0, g29= 0, g28= 1, g27= 0, g26= 42T2+ 42, g25= 0, g24= 455T4

−1050T2+ 2415, g23= 0, g22= 2548T630660T413860T2+ 119700, g21= 0, g20= 9009T8226380T6+ 171990T4343980T2+ 3221505, g19= 0, g18= 22022T10

−838530T8+ 4142460T644100T436713250T240153050, g17= 0,

g16= 39039T121844766T10+ 22431465T89075780T6259473375T42703484350T2

−370010025, g15= 0, g14= 51480T142522520T12+ 61319160T10

+39803400T8773955000T621896973000T4+ 33756345000T22893401000, g13= 0, g12= 51051T162023560T14+ 104367060T12+ 629483400T10

+6114046050T8132697164600T6+ 554979316500T4+ 319310019000T2+ 30787036875, g11= 0, g10= 38038T18589050T16+ 124369560T14+ 1700266680T12

+37748127060T10446713728300T8+ 2431707075000T6+ 1380509487000T4 +4238859255750T2+ 1299806817750, g9= 0, g8= 21021T20+ 570570T18 +112372785T16+ 1735587000T1443189665750T122318934687300T10

+10714665764250T820464596621000T6+ 35015175365625T4+ 40381027706250T2 +5540260123125, g7= 0, g6= 8372T22+ 769692T20+ 78618540T18

+570662820T16223349124600T142950615722600T12+ 16520555280600T10

−11401393059000T8+ 147193042090500T6+ 422927620447500T499598095922500T2 +17840228332500, g5= 0, g4= 2275T24+ 415380T22+ 39897270T20

−30649500T18148598863875T161555875783000T142135859799500T12

+94593530241000T1098463038821875T8+ 2611250197762500T6159203362106250T4

−83293781287500T221709549378125, g3= 0, g2= 378T26+ 114450T24 +12621420T22+ 89037900T20283320450T18+ 1545272004150T16

+12633981885000T14118201467699000T12+ 1380551057313750T10 +7814079083238750T8+ 3521850108367500T6+ 4776100863187500T4

−1406247137268750T213291560843750, g1= 0, g0= 29T28+ 13230T26 +1814295T24+ 74845260T22764250795T20204794909550T18

−3849793565625T1634193820087000T14+ 942733356807375T12 +1889980437035250T10+ 13147594251868125T8+ 3164572952887500T6

−3369410673890625T4124940671931250T2+ 3987468253125,

h30= 0, h29= 0, h28=T, h27= 0, h26= 14T342T, h25= 0, h24= 91T51610T3

−1365T, h23= 0, h22= 364T714700T5+ 13860T364260T, h21= 0, h20= 1001T9

−67452T7+ 411894T597020T32546775T, h19= 0, h18= 2002T11190190T9 +2572500T73342780T56769350T339756150T, h17= 0, h16= 3003T13

−358974T11+ 7821765T939225060T773327275T5+ 439963650T3+ 2114980875T, h15= 0, h14= 3432T15471240T13+ 13736520T11135513000T9793686600T7 +2779093800T5+ 51116751000T3+ 24754653000T, h13= 0, h12= 3003T17

−434280T15+ 14403060T13248776920T11793072350T92707651800T7+ 375945664500T5

−81098577000T3+ 297337138875T, h11= 0, h10= 2002T19275814T17

+8148168T15362872440T13114704100T1190682521300T9+ 1534457471400T7

−1772183107800T5+ 1117897625250T3+ 1493718266250)T, h9= 0, h8= 1001T21

(12)

−113190T19+ 836325T17501931080T1515705928350T13400107348900T11 +4976480045250T911450902365000T7+ 30510953731125T55820156483750T3

−21110374254375T, h7= 0, h6= 364T2324332T212084460T19

−528432660T1731926371400T15+ 150244907400T13+ 11823972489000T11

−3962494809000T9+ 7158970633500T7+ 132364254802500T5455536249717500T3

−63681344842500T, h5= 0, h4= 91T25+ 420T231450890T21337761900T19

−18543465675T17+ 274020553800T15+ 5724951088500T13+ 48513868893000T11

+171111381643125T9+ 1334157649492500T71694171881946250T5515712560737500T3

−131586452353125)T, h3= 0, h2= 14T27+ 1470T25409500T23

−111637260T213311799750T19+ 88973271450T173045655809000T15

−34947318861000T13+ 1002802178873250T11+ 1999468016831250T96800738923597500T7 +4269249343012500T51666761729806250T3+ 204690036993750T, h1= 0,

h0=T29+ 238T2743701T2514070420T231034990775T2132505382350T19 +259820563275T17+ 13855420996200T15+ 406907765530875T13+ 497730743291250T11 +1983581436965625T910570073675332500T77864084888813125T5224184326231250T3 +73103584640625)T

q30= 1, q29= 0, q28= 15T2+ 15, q27= 0, q26= 105T4630T2+ 945, q25= 0, q24= 455T67875T4+ 4725T2+ 64575, q23= 0, q22= 1365T839900T6

+103950T4+ 548100T2+ 3709125, q21= 0, q20= 3003T10114345T8+ 859950T6+ 4035150T4 +34827975T2+ 133656075, q19= 0, q18= 5005T12200970T10+ 3649275T8+ 220500T6

+277333875T4+ 959505750T2+ 1115785125, q17= 0, q16= 6435T14204435T12+ 10174815T10 +42170625T8+ 2030639625T6+ 7693410375T427357820875T2+ 24214372875, q15= 0,

q14= 6435T1659400T14+ 21035700T12+ 451672200T10+ 2902331250T8+ 79622109000T6

−319613647500T4+ 191285955000T2+ 463546951875, q13= 0, q12= 5005T18 +155925T16+ 33585300T14+ 1481098500T12+ 42118035750T10+ 639849435750T8

−1190848837500T6+ 1787210932500T4+ 4850130403125T2+ 5581517878125, q11= 0 q10= 3003T20+ 279510T18+ 40951575T16+ 2550025800T14+ 112585249350T12 +1486454400900T10+ 2935114197750T8+ 10430710605000T6+ 58973741229375T4 +49590883833750T2+ 14657286301875, q9= 0, q8= 1365T22+ 246015T20 +36850275T18+ 2719544625T16+ 98273999250T14830307854250T12

−8598553724250T10+ 211739487041250T8+ 162726680615625T6 +731900852746875T4370328202365625T2+ 93610564228125, q7= 0, q6= 455T24+ 134820T22+ 23403870T20+ 1942384500T18+ 36981653625T16

−1371507795000T14+ 3080287318500T12+ 299367020421000T10+ 3135310421315625T8 +10570433743012500T63151872128081250T4+ 1114718902762500T2

+412481438184375, q5= 0, q4= 105T26+ 46725T24+ 9856350T22 +950244750T20+ 28094731875T18+ 11015463375T167594552507500T14 +191792925292500T12+ 6041183185209375T10+ 13451797993921875T8 +29454394197768750T6+ 1342447645218750T4+ 5894807234203125T2

(13)

+118075580755453125T45861578332093750T2+ 299060118984375, q1= 0, q0=T30+ 855T28+ 275625T26+ 44441775T24+ 4060783125T22 +207533751075T20+ 5923312282125T18+ 77461769896875T16

+1691986493491875T14+ 21127132873153125T12+ 60580010182426875T10 +225021251512378125T8+ 50098108080234375T6+ 67806897644390625T4 +5881515673359375T2+ 19937341265625

(14)

Here we obtain the Akhmediev’s breather of order 5. Again, we can note the presence of N(N1)1 local maximums; the global maximum of |v|is equal to 11. We represent the modulus of v in the (x, t) coordinates and we get :

Figure 4: Solution of NLS, N=5a.

(15)

In the following cases, we only give the plots for the modulus ofv in the (x, t) coordinates.

If we choose a1 = 1, a2 = 1, a3 = 1, a4 = 1, b1 = 1, b2 = 1, b3 = 1, b4 = 1, we get :

Figure 5: Solution of NLS, N=5b.

(16)

If we choose a1 = 0, a2 = 0, a3 = 0, a4 = −0, a5 = 0, b1 = 1000000, b2 = 1000000,b3 = 1000000,b4 = 1000000, we get The shape of the modulus of v in the (x, t) coordinates is given by :

Figure 6: Solution of NLS, N=5c.

3.3 Case N=6

In the case N = 6, we realize an expansion at order 9 in ǫ. From (11), we get solutions of NLS equation. Taking the limit when ǫ0, the solution of NLS equation takes the form

v(x, t) = n(x, t)

exp(2itiϕ).

Références

Documents relatifs

Gaillard, Families of quasi-rational solutions of the NLS equation as an extension of higher order Peregrine breathers, halsh-00573955, 2011 [11] P. Gaillard, Higher order

Rational solutions to the NLS equation were written in 2010 as a quotient of two wronskians [9]; the present author constructed in [10] an- other representation of the solutions to

The present paper presents Peregrine breathers as particular case of multi-parametric families of quasi rational solutions to NLS of order N depending on 2N − 2 real parameters

Gaillard, Families of quasi-rational solutions of the NLS equation as an extension of higher order Peregrine breathers, halsh-00573955, 2011 [11] P. Gaillard, Higher order

In this paper, we use the representation of the solutions of the focusing nonlinear Schr¨ odinger equation we have constructed recently, in terms of wronskians; when we perform

Gaillard, Families of quasi-rational solutions of the NLS equation as an extension of higher order Peregrine breathers, halsh-00573955, 2011 [11] P. Gaillard, Higher order

Gaillard, Higher order Peregrine breathers and multi-rogue waves solutions of the NLS equation, halshs-00589556, 2011..

In this approach, we get an alternative way to get quasi-rational solutions of the focusing NLS equation depending on a certain number of parameters, in particular, higher