4. Let G be the Galois group of a finite field extension E of F. Let...
G. Shorter Questions Relating to Automorphisms and Galois Groups Let F be a field, and K a finite extension of F. Suppose a, b E K. Prove parts 1-3: 1 If an automorphism h of K fixes Fand a, then h fixes F(a). 3 Aside from the identity function, there are no a-fixing automorphisms of a(). [HINT: Note that aV2 contains only real numbers.] 4 Explain why the conclusion of part 3 does not contradict Theorem 1.
G. Shorter Questions...
11-1. Let E/F be a Galois extension with (E : F] > 1. (i) Must there be an intermediate field of prime degree over F? (Hint: The alternating group Ag has no subgroups of prime index (see Theorem G.37).) (ii) Same question as in (i) with the added hypothesis that Gal(E/F) is a solvable group.
(10) Let G be a finite group. Prove that if H is a proper subgroup of G, then |H| = |G|/2. (11) Let G be a group. Prove that if Hį and H2 are subgroups of G such that G= H1 U H2, then either H1 = G or H2 = G.
9. Let E be an extension field of a field F. (1) What does it mean for an element z EE being algebraic over F? (2) What does it mean for an element z E E being transcendental over F? (3) Can you find any element r e C such that r is transcendental over Q? (4) Can you prove that if a E E is algebraic over F then (F(a): F] is finite? (5) Can you prove that if...
Complete the sketch of proof for Lemma 3.17:
use theorems 3.16 and 2.5
f F is a finite dimensional separable extension of an infinite jheld Lemma 3.17. iEaa LenF. K(u) for some u ε . thern SKETCH OF PROOF. By Theorem 3.16 there is a finite dimensional Galois n field Fi of K that contains F. The Fundamental Theorem 2.5 implies that F, is finite and that the extension of K by F, has only finitely many intermediate AutA felds....
A finite field is any finite extension of Fp := Z/pZ. The characteristic of a field F is the generator of the kernel of the map ι : Z → F, ι(1) = 1. (a) Prove that there exist finite fields of order pnfor any prime p. We denote such a field Fpn. (b) Prove that Fpn has characteristic p. (c) Prove that the Frobenius map φ(a) = ap is an automorphism of Fpn . (d) If f(x) ∈ Fpn...
Abstract Algebra: Let E=.Find
the corresponding fixed fields to the subgroups of the
Galois group.
Q(V2, 3, 5
Please prove C D E F in details?
'C. Let G be a group that is DOE smDe Follow the steps indicated below; make sure to justify all an Assuming that G is simple (hence it has no proper normal subgroups), proceed as fo of order 90, The purpose of this exercise is to show, by way of contradiction. How many Sylow 3sukgroups does G have? How many Sylow 5-subgroups does G ht lain why the intersection of any two...
Only 2 and 3
1.) Let G be a finite G be a finite group of order 125, 1. e. 161-125 with the identity elemente. Assume that contains an element a with a 25 t e, Show that is cyclic 2. Solve the system of congruence.. 5x = 17 (mod 12) x = 13 mod 19) 3.) Let G be an abelian. group Let it be a subgroup o G. Show that alt -Ha for any a EG