Hermitian Eigenvalues Calculator

Analyze Hermitian matrices with intuitive complex input fields. See ordered eigenvalues, invariants, and chart insights. Save tables, summaries, plots, and exports for reports quickly.

Enter a 3x3 Hermitian Matrix

Only the upper triangle is required. Lower entries are built automatically as complex conjugates.

Real diagonal entry.
Real diagonal entry.
Real diagonal entry.
Real part of a12.
Imaginary part of a12.
Controls output rounding.
Real part of a13.
Imaginary part of a13.
Real part of a23.
Imaginary part of a23.

Formula Used

For a 3x3 Hermitian matrix A, the calculator forms the characteristic equation:

λ³ − (tr A)λ² + c₂λ − det(A) = 0

With upper-triangle entries a12, a13, and a23, the second coefficient is:

c₂ = a11a22 + a11a33 + a22a33 − |a12|² − |a13|² − |a23|²

The determinant is:

det(A) = a11a22a33 + 2Re(a12·a23·conj(a13)) − a11|a23|² − a22|a13|² − a33|a12|²

Because Hermitian matrices have real eigenvalues, the cubic is solved in real form and returned in ascending order.

How to Use This Calculator

  1. Enter the three real diagonal values a11, a22, and a33.
  2. Enter real and imaginary parts for a12, a13, and a23.
  3. Choose the output precision from 2 to 8 decimals.
  4. Click Calculate eigenvalues to generate the ordered spectrum.
  5. Review the summary metrics, matrix table, diagnostic checks, and Plotly graph.
  6. Use the CSV or PDF buttons to export the calculated output.

Example Data Table

Example a11 a22 a33 a12 a13 a23 Eigenvalues
Sample 3x3 Hermitian matrix 4 5 6 1 + 2i 0 - 1i 2 + 1i 1.1769, 5.8926, 7.9305

Frequently Asked Questions

1. What is a Hermitian matrix?

A Hermitian matrix equals its own conjugate transpose. Diagonal entries are real, and each lower-triangle entry is the complex conjugate of the matching upper-triangle entry.

2. Why are the eigenvalues always real?

Hermitian matrices have a special symmetry in complex inner-product spaces. That structure guarantees every eigenvalue is real, which makes them important in physics, optimization, and numerical analysis.

3. Why does this calculator ask only for the upper triangle?

The lower triangle is determined automatically by Hermitian symmetry. Entering only the upper-triangle complex values avoids mismatched pairs and keeps the matrix valid by construction.

4. What does the trace tell me?

The trace is the sum of diagonal entries. For any square matrix, it also equals the sum of the eigenvalues, so it is a quick correctness check.

5. What is the spectral radius?

The spectral radius is the largest absolute eigenvalue. It helps judge growth, stability, and dominant modes in many matrix-based systems.

6. How do I know if the matrix is positive definite?

If every eigenvalue is positive, the matrix is positive definite. If the smallest eigenvalue is zero or positive, it is positive semidefinite.

7. What does the eigenvalue spread measure?

The spread is the largest eigenvalue minus the smallest eigenvalue. It shows how wide the spectrum is and how separated the extreme modes are.

8. Can I use this for larger Hermitian matrices?

This page is designed for 3x3 Hermitian matrices. Larger matrices usually need numerical methods such as QR, divide-and-conquer, or iterative eigensolvers.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.