Let ϕ be a ℤ/2ℤ-spin structure on closed oriented surface Σ g of genus g≥4. We determine generating set the stabilizer in mapping class group consisting Dehn twists about an explicit collection 2g+1 curves . If g=3 then we odd ℤ/4ℤ-spin 6 curves.

In this work we discuss the calculation of spin-density matrix from fundamental spin principles as implemented in COLUMBUS Program System employing graphical unitary group approach (GUGA). First, a general equation for is derived terms one-and two-particle reduced density matrices, quantities that are spin-independent and readily available within GUGA formalism. Next, evaluation using Shavitt l...

Renormalization group methods are well-established tools for the (numerical) investigation of low-energy properties correlated quantum many-body systems, allowing us to capture their scale-dependent nature. The functional renormalization (FRG) allows continuously evolve a microscopic model action an effective as function decreasing energy scales via exact flow equation, which is then approximat...