Function Spaces
This quiz covers fundamental concepts in functional analysis including function spaces (normed, Banach, and Hilbert spaces) and properties of linear operators (compact, Fredholm, trace class, Hilbert-Schmidt, positive, projection, unitary, normal, self-adjoint, bounded, and closed operators).
Questions
Which of the following is NOT a function space?
- The set of all continuous functions on the interval [0, 1]
- The set of all polynomials with real coefficients
- The set of all functions that are differentiable at least once
- The set of all functions that are integrable on the interval [0, 1]
Which of the following is a property of a normed space?
- It is complete
- It is closed under addition and scalar multiplication
- It has a norm that satisfies the triangle inequality
- All of the above
Which of the following is an example of a Banach space?
- The space of continuous functions on the interval [0, 1]
- The space of differentiable functions on the interval [0, 1]
- The space of integrable functions on the interval [0, 1]
- All of the above
Which of the following is an example of a Hilbert space?
- The space of square-integrable functions on the interval [0, 1]
- The space of continuous functions on the interval [0, 1]
- The space of differentiable functions on the interval [0, 1]
- The space of integrable functions on the interval [0, 1]
Which of the following is a property of a compact operator?
- It is a bounded linear operator
- Its spectrum is a compact set
- It has a finite-dimensional range
- All of the above
Which of the following is a property of a Fredholm operator?
- It is a bounded linear operator
- Its index is zero
- Its spectrum is a closed set
- All of the above
Which of the following is a property of a trace class operator?
- It is a compact operator
- Its trace is finite
- Its spectrum is a discrete set
- All of the above
Which of the following is a property of a Hilbert-Schmidt operator?
- It is a compact operator
- Its Hilbert-Schmidt norm is finite
- Its spectrum is a compact set
- All of the above
Which of the following is a property of a positive operator?
- Its spectrum is a subset of the non-negative real numbers
- It is a self-adjoint operator
- It has a positive trace
- All of the above
Which of the following is a property of a projection operator?
- It is a self-adjoint operator
- Its range is a closed subspace
- Its kernel is a closed subspace
- All of the above
Which of the following is a property of a unitary operator?
- It is a bounded linear operator
- Its inverse is also unitary
- Its spectrum is a subset of the unit circle
- All of the above
Which of the following is a property of a normal operator?
- It is a bounded linear operator
- It commutes with its adjoint
- Its spectrum is a closed set
- All of the above
Which of the following is a property of a self-adjoint operator?
- It is a normal operator
- Its spectrum is a subset of the real numbers
- Its eigenvectors are orthogonal
- All of the above
Which of the following is a property of a bounded linear operator?
- It is a continuous linear operator
- Its range is a closed subspace
- Its kernel is a closed subspace
- All of the above
Which of the following is a property of a closed linear operator?
- Its graph is a closed subspace
- Its range is a closed subspace
- Its kernel is a closed subspace
- All of the above