let $r=oplus_{nin bbb n_0}r_n$ be a noetherian homogeneous ring with local base ring $(r_0,frak{m}_0)$, $m$ and $n$ two finitely generated graded $r$-modules. let $t$ be the least integer such that $h^t_{r_+}(m,n)$ is not minimax. we prove that $h^j_{frak{m}_0r}(h^t_{r_+}(m,n))$ is artinian for $j=0,1$. also, we show that if ${rm cd}(r_{+},m,n)=2$ and $tin bbb n_0$, then $h^t_{frak{m}_0r}(h^2_{...

We obtain an explicit Iwasawa decomposition of the symplectic matrices, complex or real, in terms of the Cholesky factorization for positive definite n×n matrices. We also provide a MATLAB program to compute the decomposition. 1. Iwasawa decomposition of the symplectic groups Let G be the real (noncompact) symplectic group [3, p.129] (the notation there is Spn), [4, p.265] G := Spn(R) = {g ∈ SL...

These are a very preliminary (and incomplete!) version of the author’s lectures for the 2018 Arizona Winter School on Iwasawa Theory.

Let A be the inverse limit of the p-part of the ideal class groups in a Zpextension K∞/K. Greenberg conjectures that if r is maximal, then A is pseudo-null as a module over the Iwasawa algebra Λ (that is, has codimension at least 2). We prove this conjecture in the case that K is the field of p-th roots of unity, p has index of irregularity 1, satisfies Vandiver’s conjecture, and satisfies a mi...

Iwasawa’s classical asymptotical formula relates the orders of the p-parts Xn of the ideal class groups along a Zp-extension F∞/F of a number field F , to Iwasawa structural invariants λ and μ attached to the inverse limit X∞ = lim ← Xn. It relies on ”good” descent properties satisfied by Xn. If F is abelian and F∞ is cyclotomic it is known that the p-parts of the order of the global units modu...

We prove an anticyclotomic Iwasawa main conjecture proposed by Perrin-Riou for Heegner points semi-stable elliptic curves E over a quadratic imaginary field K satisfying certain generalized hypothesis, at ordinary prime p. It states that the square of index family in equals characteristic ideal torsion part its Bloch-Kato Selmer group (see Theorem 1.3 precise statement). As byproduct we also eq...

Our objective in this paper is to prove a rather broad generalization of some classical theorems in Iwasawa theory. We begin by recalling two of those old results. The first is a theorem of Iwasawa, which we state in terms of Galois cohomology. Suppose that K is a totally real number field, that F is a totally complex quadratic extension of K, and that ψ is the nontrivial character of Gal(F/K),...