On Classification of Symmetry Reductions for the Eikonal Equation
Abstract
:1. Introduction
2. The Lie Algebra of the Group and Its Nonconjugate Subalgebras
3. Results
3.1. Lie Algebras of the Type
3.1.1. Reductions to Algebraic Equations
- (1)
- Ansatz:Reduced equation:Solution of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solution of the eikonal equation:As we see, the left hand sides of the Ansatzes (1)–(3) are polinomials in invariant . The reduced equations are also polinomials in ω, but with the constant coefficients. The solutions of the eikonal equation are also polinomials in variable with the constant coefficients.
- (4)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (5)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.1.2. Reductions to Linear ODEs
- (1)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:Let us note, that in the cases (1)–(3) we obtained the same reduced equations.
- (4)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (5)
- Ansatz:The reduced equation:Solutions of the reduced equation:Solutions on the eikonal equation:
- (6)
- Ansatz:The reduced equation:Solutions of the reduced equation:Solutions on the eikonal equation:
3.1.3. Reductions to Equations, Which Can Be Split on Two Linear ODEs
- (1)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (5)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (6)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:Let us note that, in the cases (1)–(6), we obtained the same reduced equations. The solutions of the eikonal equation are also the same.
- (7)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (8)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (9)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.1.4. Reductions to Nonlinear ODEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (5)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.1.5. There Are No Reductions
- (1)
- (2)
- (3)
- (4)
- (5)
- (6)
3.2. Lie Algebras of the Type
3.2.1. Reductions to Equations, Which Can Be Split on Two Linear ODEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.2.2. Reductions to Nonlinear ODEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (5)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.2.3. There Are No Reductions
- (1)
- (2)
- (3)
3.3. Lie Algebras of the Type
3.3.1. Reductions to Algebraic Equations
- (1)
- Ansatz:Reduced equation:Solution of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solution of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solution of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solutions of the eikonal equation:
- (5)
- Ansatz:Reduced equation:Solutions of the eikonal equation:As we see, the left hand sides of the Ansatzes (1)–(5) are polinomials in invariant . The reduced equations are also polinomials in variable ω, but with the constant coefficients. The solutions of the eikonal equation are also polinomials in variable with the constant coefficients.
- (6)
- Ansatz:Reduced equation:Solution of the eikonal equation:
- (7)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.3.2. Reductions to Equations, Which Can Be Split on Two Linear ODEs
- (1)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (5)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
3.3.3. Reductions to Nonlinear ODEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
3.3.4. There Are No Reductions
3.4. Lie Algebras of the Type
3.4.1. Reductions to Nonlinear ODEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.4.2. There Are No Reductions
3.5. Lie Algebras of the Type
3.5.1. Reductions to Equations, Which Can Be Split on Two Linear ODEs
3.5.2. Reductions to Nonlinear ODEs
- (1)
- Ansatz:The reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.5.3. There Are No Reductions
3.6. Lie Algebras of the Type
3.6.1. There Are No Reductions
- (1)
- : ;
- (2)
- : ;
- (3)
- : ;
- (4)
3.7. Lie Algebras of the Type
3.8. Lie Algebras of the Type
3.8.1. Reductions to Linear ODEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
3.8.2. Reductions to Equations, Which Can Be Split on Two Linear ODEs
- (1)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solution of the reduced equation:Solution of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (4)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (5)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (6)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (7)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.8.3. Reductions to Nonlinear ODEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (3)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
3.8.4. Reductions to PDEs
- (1)
- Ansatz:Reduced equation:Solutions of the reduced equation:Solutions of the eikonal equation:
- (2)
- Ansatz:The reduced equation:Solutions of the reduced equation:Solutions on the eikonal equation:
3.8.5. There Are No Reductions
- (1)
- (2)
3.9. Lie Algebras of the Type
3.9.1. Reductions to Equations, Which Can Be Split on Two Linear ODEs
3.9.2. Reductions to Nonlinear ODEs
3.10. Lie Algebras of the Type
3.10.1. Reductions to PDEs
3.11. Lie Algebras of the Type
3.11.1. Reductions to Equations, Which Can Be Split on Two Linear ODEs
3.11.2. Reductions to PDEs
4. Conclusions
- Reductions to algebraic equations are induced by some subalgebras of the types , ;
- Reductions to linear ODEs are induced by some subalgebras of the types , ;
- Reductions to equations, which can be split on two linear ODEs, are induced by some subalgebras of the types , , , , , , ;
- Reductions to nonlinear ODEs are induced by subalgebras of the type as well as by some subalgebras of the types , , , , , ;
- Reductions to PDEs are induced by subalgebras of the type as well as by some subalgebras of the types , ;
- From invariants of subalgebras of the type as well as of some subalgebras of the types , , , , , , we cannot construct ansatzes reducing the eikonal equation;
- There are no nonconjugate subalgebras of the Lie algebra of the group of the type .
Author Contributions
Conflicts of Interest
References
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Fedorchuk, V.; Fedorchuk, V. On Classification of Symmetry Reductions for the Eikonal Equation. Symmetry 2016, 8, 51. https://doi.org/10.3390/sym8060051
Fedorchuk V, Fedorchuk V. On Classification of Symmetry Reductions for the Eikonal Equation. Symmetry. 2016; 8(6):51. https://doi.org/10.3390/sym8060051
Chicago/Turabian StyleFedorchuk, Vasyl, and Volodymyr Fedorchuk. 2016. "On Classification of Symmetry Reductions for the Eikonal Equation" Symmetry 8, no. 6: 51. https://doi.org/10.3390/sym8060051
APA StyleFedorchuk, V., & Fedorchuk, V. (2016). On Classification of Symmetry Reductions for the Eikonal Equation. Symmetry, 8(6), 51. https://doi.org/10.3390/sym8060051