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P . P . Fiziev. Nis 28.12.2007. Department of Theoretical Physics University of Sofia. Exact Solutions of Regge-Wheeler and Teukolsky Equations.
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P. P. Fiziev Nis 28.12.2007 Department of Theoretical Physics University of Sofia
Exact Solutions of Regge-Wheeler and Teukolsky Equations • The Regge-Wheeler (RW) equation describes the axial perturbations of Schwarzschild metric in linear approximation. • TheTeukolsky Equations describe perturbations of Kerr metric. • We present here: • Their exact solutions in terms of confluent Heun’s functions. • The basic properties of the RW general solution. • Novel analytical approach and numerical techniques for study of • different boundary problems which correspond to quasi-normal • modes of black holes and other simple models of compact objects. • The exact solutions of RW equation in the SchwarzschildBH interior. • The exact solutions of Teukolsky master equations (TME). • New singular exact solutions of TME and their application to the theory • of therelativistic jets.
Linear perturbations of Schwarzschild metric1957 Regge-Wheeler equation (RWE): The potential: The type of perturbations:S=2 - GW, s=1-vector, s=0 – scalar; The tortoise coordinate: The Schwarzschild radius: The area radius: 1758 Lambert W(z) function: W exp(W) = z
The standard ansatz separates variables. One needs proper boundary conditions (BC). The “stationary” RWE: Known Numerical studies and approximate analytical methods for BH BC. See the wonderful reviews: V. Ferrary (1998), K. D. Kokkotas & B. G. Schmidt (1999), H-P. Nollert (1999). V. Ferrari, L. Gualtieri (2007). and some basic results in: S. Chandrasekhar & S. L. Detweiler (1975), E. W. Leaver (1985), N. Andersson (1992), and many others!
Exact mathematical treatment: PPF, In r variable RWE reads: The ansatz: reduces the RWE to aspecific type of 1889 Heun equation: with
Thus one obtains a confluent Heun equation with: 2regular singular points: r=0 and r=1, and 1irregular singular point: in the complex plane Note that after all the horizon r=1turns to be a singular point in contrary to the widespread opinion. From geometrical point of view the horizon is indeed a regular point (or a 2D surface) in the SchwarzschildRiemannian space-time manifold: It is a singularity, which is placed in the (co) tangent fiber of the (co) tangent foliation: and is “invisible” from point of view of the base .
The local solutions (one regular + one singular) around the singular points:X=0, 1, Frobenius type of solutions: Tome (asymptotic) type of solutions:
Different types of boundary problems: I. BH boundary problems: two-singular-points boundary. Up to recently onlythe QNM problem on [1, ), i.e. on the BH exterior, was studied numerically and using different analytical approximations. We present here exact treatment of this problem, as well as of the problems on [0,1] (i.e. in BH interior), and on [0, ).
QNM on [0, ) by Maple 10: Using the condition: -i One obtains by Maple 10 for the first 5 eigenvalues: and 12 figures - for n=0:
Perturbations of theBHinteriorMatzner (1980), PPF gr-qc/0603003, PPF JournalPhys. 66, 0120016, 2006. For one introduces interior time: and interior radial variable: . Then: where:
The continuous spectrum Normal modes in Schwarzschild BH interior: A basis for Fourier expansion of perturbations of general form in the BH interior
The special solutions with : • These: • form an orthogonal basis with respect to the weight: • do not depend on the variable . • are the only solutions, which are finite at both singular ends of the interval .
The discrete spectrum - pure imaginary eigenvalues: • Ferrari-Mashhoon transformation: • For : • Additional parameter – mixing angle : • Spectral condition – for arbitrary : “falling at the centre” problem operator with defect
Numerical resultsFor the first 18 eigenvalues one obtains: For alpha =0 – no outgoing waves: Two potential weels –> two series: Two series: n=0,…,6; and n=7,… exist. The eigenvalues In them are placed around the lines and .
Perturbations of Kruskal-Szekeres manifold In this case the solution can be obtained from functions imposing the additionalcondition which may create a spectrum: It annulates the coming from the space-infinity waves. The numerical study for the case l=s=2 shows that it is impossible to fulfill the last condition and to have some nontrivial spectrum of perturbations in Kruskal-Szekeres manifold.
II. Regular Singular-two-point Boundary Problems at Physical meaning: Total reflection of the waves at the surface with area radius : PPF, Dirichlet boundary Condition at : The solution: The simplest model of a compact object
The Spectral condition: Numerical results: The trajectories in of The trajectory of thebasic eigenvalue in and the BH QNM(blackdots):
TheKerr (1963) Metric In Boyer - Lindquist (1967) - {+,-,-,-} coordinates:
The Kerr solution yieldsmuch more complicated structures then the Schwarzschild one: The event horizon, the ergosphere, the Cauchy horizon and the ring singularity The event horizon, the Cauchyhorizon and the ring singularity
Simple algebraic and differential invariants for the Kerr solution:Let is theWeyltensor, - its dual - Density for the Chern - Pontryagin characteristic class - Density for the Euler characteristic class Let • Two independent • algebraic invariants and Then the differential invariants: CAN LOCALLY SEE -The TWO HORIZONS -The ERGOSPHERE
gtt =1 - 2M /, where M is theBHmassForgtt = 0.7, 0.0, -0.1, -0.3, -0.5, -1.5, -3.0, - :
Linear perturbations of Kerr metric S. Teukolsky, PRL, 29, 1115 (1972): Separation of thevariables: A trivial dependence on the Killing directions - . (!) : From stability reasons one MUST have:
1972 Teukolsky master equations (TME): The angular equation: Spin: S=-2,-1,0,1,2. The radial equation: and are two independent parameters
Up to now only numerical results and approximate methods were studied • First results: • S. Teukolsky, PRL, 29, 1115 (1972). • W Press, S. Teukolsky,AJ185, 649 (1973). • E. Fackerell, R. Grossman, JMP, 18, 1850 (1977). • E. W. Leaver, Proc. R. Soc. Lond. A 402, 285, (1985). • E. Seidel, CQG, 6, 1057 (1989). • For more recent results see, for example: • H. Onozawa, gr-qc/9610048. • E. Berti, V. Cardoso, gr-qc/0401052. • and the references therein.
Two independent exactregular solutions of the angular Teukolsky equation are: An obvious symmetry:
The regularity of the solutions simultaneously at the both singular ends of the interval [0,Pi] is: W [ , ] = 0, W– THE WRONSKIAN , or explicitly: It yields the relation: whith unfortunately explicitlyunknown function .
Explicit form of the radial Teukolsky equation where we are using the standard • Note the symmetry between and in the radial TME • and are regularsyngular points of the radial TME • is an irregular singular point of the radial TME
Two independent exact solutions of the radial Teukolsky equation in outer domain are:
BHboundary conditions at the event horizon: The waves can go only into the horizon. Consequence: - only the solution obeys BH BC at the EH. - only the solution obeys BH BC at the EH. If => An additional physical clarification.
Boundary conditions at space infinity – only going to waves: If , then: If , then:
As a result one has to solve the system of equations forand : () 1) For any : 2) and when : or => a nontrivial numerical problem.
Making use of indirect methods: H. Onozawa, 1996
TheRelativistic Jets: The Most Powerful and Misterious Phenomenon in the Universe, which are observed at different scales:1. Around single neutron star (~10-1000 AU)2. In binary BH–Star, and Star-Star systems3. In Gamma Ray Burst (GRB) (~1 kPs) 4. Around galactic nuclei (~1 MPs)5. Around galactic collisions (~10 MPs) 6. Around galactic clusters (~200 Mps) => UNIVERSAL NATURE ???
A hyper nova 08.09.05 (distance 11.7 bills lys) FormationofWHAT???: BH???,OR ???VU6APFLG.mov Series ofexplosions observed!
The Jet from M87 2006 News Jets from GRB060418 and GRB060607A: ~ 200 Earth masses with velocity0.999997 c
Today’s theoretical models Relativistic Jet Massive Black Hole Common feature: Rotating (Strong) Gravitational Field Molecular Torus Accretion Disk
Singular solutions of the angular Teukolsky equation Besides regular solutions the angular TME has singular solutions: and
The singularities can be essentially weakened if one works with PolynomialHeun’s functions(analogy with Hydrogen atom): Three terms recurrence relation: Polynomial solutions with: and Defines symple functions
Double wafes(with different velocities):amplitude waveandphase wave Regular solution of angular TME with three nodes: The phase wave: The amplitude wave:
Double wafes(with different velocities):amplitude waveandphase wave Jet solutions of the angular TME The phase wave: The amplitude wave:
The distribution of the eigenvalues in the complex plane for the singular case s=-2, m=1 with F(z)=z F(z)=1/z
The singular cases=-2, m=1with,2M=1,a/M=0.99 Re(omega) Im(omega) 0.17288 -0.00944 0.18630 -0.05564 0.22508 -0.07692 0.30106 -0.09009 0.33533 -0.09881 0.38281 -0.09909 0.35075 -0.12008 0.27110 -0.13029 0.47609 -0.15200 0.47601 -0.16000 0.60080 -0.18023 0.56077 -0.25076 0.50049 -0.29945 0.40205 -0.37716