The analytic renormalization group

The Analytic Renormalization Group

Finite temperature Euclidean two-point functions in quantum mechanics or quantum field theory are characterized by a discrete set of Fourier coefficients Gk, k ∈ Z, associated with the Matsubara frequencies νk = 2πk/β. We show that analyticity implies that the coefficients Gk must satisfy an infinite number of model-independent linear equations that we write down explicitly. In particular, we c...

Analytic response theory for the density matrix renormalization group.

We propose an analytic response theory for the density matrix renormalization group, whereby response properties correspond to analytic derivatives of density matrix renormalization group observables with respect to the applied perturbations. Both static and frequency-dependent response theories are formulated and implemented. We evaluate our pilot implementation by calculating static and frequ...

Renormalization Group Renormalization Group

Analytic theory of Hund’s metals: A renormalization group perspective

We study the emergence of quasiparticles in Hund’s metals with an SU(M) × SU(N )-symmetric Kondo impurity model carrying both spin and orbital degrees of freedom. We show that the coupling of the impurity spin to the conduction electrons can be ferromagnetic, notably for hole-doped iron pnictides. We derive the weak-coupling renormalization group (RG) equations for arbitrary representations of ...

Time-Dependent Real-Space Renormalization Group Method

In this paper, using the tight-binding model, we extend the real-space renormalization group method to time-dependent Hamiltonians. We drive the time-dependent recursion relations for the renormalized tight-binding Hamiltonian by decimating selective sites of lattice iteratively. The formalism is then used for the calculation of the local density of electronic states for a one dimensional quant...