Inner product of complex numbrs

In summary, the conversation discusses the concept of inner products and their relationship to matrices. It is mentioned that when a matrix is multiplied by its Hermitian (conjugate transpose), the resulting product has the same integer down the main diagonal, indicating that the eigenvalues are all the same. It is clarified that this only applies to matrices that are self adjoint or Hermitian, meaning they are the same after mirroring on the main diagonal and complex conjugation. The term "Hermitian of a matrix" is questioned and its definition is explained.
  • #1
DmytriE
78
0
I would like if someone could either verify or clarify my thinking about inner products.

There is a matrix, V that is m x n, that is made up of complex numbers. When matrix V is multiplied by its hermitian then the product is a matrix with the same integer down the main diagonal (i.e. Eigenvalues are all the same).
 
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  • #2
If you mean by its Hermitian the conjugate transpose. There are matrices that are self adjoined, and don't change under that operation. When you multiply such a matrix by its conjugate transpose the eigenvalues are squared.
 
  • #3
What do you mean by self adjoining?
 
  • #4
The definition of a self adjoint or Hermitian matrix is, that the matrix is the same after mirroring on the main diagonal and complex conjugation. What you mean by Hermitian of a matrix I don't know.
 
  • #5


The inner product of two complex numbers, denoted as <a,b>, is defined as <a,b> = a* x b, where a* represents the complex conjugate of a. This definition holds true for matrices as well. When two matrices are multiplied together, their inner product is equal to the sum of the products of each corresponding element in the matrices, with the complex conjugate of the first matrix element multiplied by the second matrix element. In other words, the inner product of two matrices is a complex number that represents the measure of similarity between the two matrices.

In the context of matrix V and its hermitian, the inner product of V and its hermitian can be represented as <V,V*>. This inner product will result in a matrix with integer values along the main diagonal, as stated in the content. This is because the complex conjugates of each element in V will cancel out, leaving only the real parts of the complex numbers to be multiplied together.

It is important to note that the inner product of complex numbers and matrices is a generalization of the dot product in Euclidean space. Just like the dot product, the inner product of complex numbers and matrices also follows the properties of linearity, commutativity, and positive definiteness.

In summary, the inner product of complex numbers and matrices is a useful tool in measuring the similarity between two entities. It is defined as the sum of the products of each corresponding element, with the complex conjugate of the first element multiplied by the second element. In the case of matrix V and its hermitian, the inner product results in a matrix with integer values along the main diagonal.
 

FAQ: Inner product of complex numbrs

What is the definition of an inner product of complex numbers?

The inner product of two complex numbers is a mathematical operation that takes two complex numbers as inputs and returns a single complex number as the output. It is defined as the sum of the products of the complex conjugate of the first number and the second number, and vice versa. In other words, it measures the similarity between two complex numbers in terms of both their magnitude and phase.

How is the inner product of complex numbers calculated?

The inner product of two complex numbers, denoted as ⟨a, b⟩, is calculated using the formula ⟨a, b⟩ = a* x b + a x b*, where a* represents the complex conjugate of a and b* represents the complex conjugate of b. This formula can also be written in terms of the real and imaginary parts of the complex numbers, as ⟨a, b⟩ = (a1 x b1) + (a2 x b2)i, where a = a1 + a2i and b = b1 + b2i.

What properties does the inner product of complex numbers have?

The inner product of complex numbers has several properties, including linearity, conjugate symmetry, and positive definiteness. Linearity means that the inner product is distributive and additive, meaning that ⟨a, b + c⟩ = ⟨a, b⟩ + ⟨a, c⟩ and ⟨a, kb⟩ = k⟨a, b⟩, where k is a constant. Conjugate symmetry means that ⟨a, b⟩ = ⟨b, a⟩*, and positive definiteness means that &lang>a, a⟩ > 0 for all non-zero complex numbers a.

How is the inner product of complex numbers used in applications?

The inner product of complex numbers is used in a variety of applications, including signal processing, quantum mechanics, and geometry. In signal processing, it is used to calculate the energy or power of a signal, which is important in areas such as telecommunications and audio processing. In quantum mechanics, it is used to calculate the probability of measuring a particular state of a quantum system. In geometry, it is used to calculate the angle between two complex vectors or to determine if two vectors are orthogonal.

Are there any other types of inner products besides the one for complex numbers?

Yes, there are several other types of inner products, including those for real numbers, matrices, and functions. The inner product for real numbers is similar to the one for complex numbers, but it only involves the real parts of the numbers. The inner product for matrices involves multiplying two matrices and then taking the trace (sum of the diagonal elements). The inner product for functions involves integrating the product of two functions over a specified interval. Each of these types of inner products has their own unique properties and applications.

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