start on postnikov tower of spectra

This commit is contained in:
Floris van Doorn 2017-06-29 15:48:43 +01:00
parent f8f0157df5
commit 057980ca1f
6 changed files with 126 additions and 28 deletions

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@ -633,8 +633,8 @@ namespace spectrum
open int
parameters (ub : ) (lb : )
(Aub : Πs n, s ≥ ub + 1 → is_equiv (f s n))
(Alb : Πs n, s ≤ lb n → is_contr (πₛ[n] (A s)))
(Aub : Π(s n : ), s ≥ ub + 1 → is_equiv (f s n))
(Alb : Π(s n : ), s ≤ lb n → is_contr (πₛ[n] (A s)))
definition B : I →
| (n, s) := max0 (s - lb n)

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@ -570,24 +570,4 @@ namespace EM
abstract (EMadd1_functor_gcompose φ φ⁻¹ᵍ n)⁻¹* ⬝* EMadd1_functor_phomotopy proof right_inv φ qed n ⬝*
EMadd1_functor_gid H n end
/- Eilenberg MacLane spaces are the fibers of the Postnikov system of a type -/
definition postnikov_map [constructor] (A : Type*) (n : ℕ₋₂) : ptrunc (n.+1) A →* ptrunc n A :=
ptrunc.elim (n.+1) !ptr
open fiber
definition pfiber_postnikov_map (A : Type*) (n : ) : pfiber (postnikov_map A n) ≃* EM_type A (n+1) :=
begin
symmetry, apply EM_type_pequiv,
{ symmetry, refine _ ⬝g ghomotopy_group_ptrunc (n+1) A,
exact chain_complex.LES_isomorphism_of_trivial_cod _ _
(trivial_homotopy_group_of_is_trunc _ (self_lt_succ n))
(trivial_homotopy_group_of_is_trunc _ (le_succ _)) },
{ apply is_conn_fun_trunc_elim, apply is_conn_fun_tr },
{ have is_trunc (n+1) (ptrunc n.+1 A), from !is_trunc_trunc,
have is_trunc ((n+1).+1) (ptrunc n A), by do 2 apply is_trunc_succ, apply is_trunc_trunc,
apply is_trunc_pfiber }
end
end EM

116
homotopy/serre.hlean Normal file
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@ -0,0 +1,116 @@
import ..algebra.module_exact_couple .strunc
open eq spectrum trunc is_trunc pointed int EM algebra left_module fiber lift
/- Eilenberg MacLane spaces are the fibers of the Postnikov system of a type -/
definition postnikov_map [constructor] (A : Type*) (n : ℕ₋₂) : ptrunc (n.+1) A →* ptrunc n A :=
ptrunc.elim (n.+1) !ptr
definition ptrunc_functor_postnikov_map {A B : Type*} (n : ℕ₋₂) (f : A →* B) :
ptrunc_functor n f ∘* postnikov_map A n ~* ptrunc.elim (n.+1) (!ptr ∘* f) :=
begin
fapply phomotopy.mk,
{ intro x, induction x with a, reflexivity },
{ reflexivity }
end
section
open nat is_conn group
definition pfiber_postnikov_map (A : Type*) (n : ) :
pfiber (postnikov_map A n) ≃* EM_type A (n+1) :=
begin
symmetry, apply EM_type_pequiv,
{ symmetry, refine _ ⬝g ghomotopy_group_ptrunc (n+1) A,
exact chain_complex.LES_isomorphism_of_trivial_cod _ _
(trivial_homotopy_group_of_is_trunc _ (self_lt_succ n))
(trivial_homotopy_group_of_is_trunc _ (le_succ _)) },
{ apply is_conn_fun_trunc_elim, apply is_conn_fun_tr },
{ have is_trunc (n+1) (ptrunc n.+1 A), from !is_trunc_trunc,
have is_trunc ((n+1).+1) (ptrunc n A), by do 2 apply is_trunc_succ, apply is_trunc_trunc,
apply is_trunc_pfiber }
end
end
definition postnikov_map_natural {A B : Type*} (f : A →* B) (n : ℕ₋₂) :
psquare (postnikov_map A n) (postnikov_map B n)
(ptrunc_functor (n.+1) f) (ptrunc_functor n f) :=
!ptrunc_functor_postnikov_map ⬝* !ptrunc_elim_ptrunc_functor⁻¹*
definition encode_ap1_gen_tr (n : ℕ₋₂) {A : Type*} {a a' : A} (p : a = a') :
trunc.encode (ap1_gen tr idp idp p) = tr p :> trunc n (a = a') :=
by induction p; reflexivity
definition ap1_postnikov_map (A : Type*) (n : ℕ₋₂) :
psquare (Ω→ (postnikov_map A (n.+1))) (postnikov_map (Ω A) n)
(loop_ptrunc_pequiv (n.+1) A) (loop_ptrunc_pequiv n A) :=
have psquare (postnikov_map (Ω A) n) (Ω→ (postnikov_map A (n.+1)))
(loop_ptrunc_pequiv (n.+1) A)⁻¹ᵉ* (loop_ptrunc_pequiv n A)⁻¹ᵉ*,
begin
refine _ ⬝* !ap1_ptrunc_elim⁻¹*, apply pinv_left_phomotopy_of_phomotopy,
fapply phomotopy.mk,
{ intro x, induction x with p, exact !encode_ap1_gen_tr⁻¹ },
{ reflexivity }
end,
this⁻¹ᵛ*
-- definition postnikov_map_int (X : Type*) (k : ) :
-- ptrunc (maxm2 (k + 1)) X →* ptrunc (maxm2 k) X :=
-- begin
-- induction k with k k,
-- exact postnikov_map X k,
-- exact !pconst
-- end
-- definition postnikov_map_int_natural {A B : Type*} (f : A →* B) (k : ) :
-- psquare (postnikov_map_int A k) (postnikov_map_int B k)
-- (ptrunc_int_functor (k+1) f) (ptrunc_int_functor k f) :=
-- begin
-- induction k with k k,
-- exact postnikov_map_natural f k,
-- apply psquare_of_phomotopy, exact !pcompose_pconst ⬝* !pconst_pcompose⁻¹*
-- end
-- definition postnikov_map_int_natural_pequiv {A B : Type*} (f : A ≃* B) (k : ) :
-- psquare (postnikov_map_int A k) (postnikov_map_int B k)
-- (ptrunc_int_pequiv_ptrunc_int (k+1) f) (ptrunc_int_pequiv_ptrunc_int k f) :=
-- begin
-- induction k with k k,
-- exact postnikov_map_natural f k,
-- apply psquare_of_phomotopy, exact !pcompose_pconst ⬝* !pconst_pcompose⁻¹*
-- end
-- definition pequiv_ap_natural2 {X A : Type} (B C : X → A → Type*) {a a' : X → A}
-- (p : a ~ a')
-- (s : X → X) (f : Πx a, B x a →* C (s x) a) (x : X) :
-- psquare (pequiv_ap (B x) (p x)) (pequiv_ap (C (s x)) (p x)) (f x (a x)) (f x (a' x)) :=
-- begin induction p using homotopy.rec_on_idp, exact phrfl end
-- definition pequiv_ap_natural3 {X A : Type} (B C : X → A → Type*) {a a' : A}
-- (p : a = a')
-- (s : X → X) (x : X) (f : Πx a, B x a →* C (s x) a) :
-- psquare (pequiv_ap (B x) p) (pequiv_ap (C (s x)) p) (f x a) (f x a') :=
-- begin induction p, exact phrfl end
-- definition postnikov_smap (X : spectrum) (k : ) :
-- strunc (k+1) X →ₛ strunc k X :=
-- smap.mk (λn, postnikov_map_int (X n) (k + n) ∘* ptrunc_int_change_int _ !norm_num.add_comm_middle)
-- (λn, begin
-- exact sorry
-- -- exact (_ ⬝vp* !ap1_pequiv_ap) ⬝h* (!postnikov_map_int_natural_pequiv ⬝v* _ ⬝v* _) ⬝vp* !ap1_pcompose,
-- end)
-- section atiyah_hirzebruch
-- parameters {X : Type*} (Y : X → spectrum)
-- definition atiyah_hirzebruch_exact_couple : exact_couple r spectrum.I :=
-- @exact_couple_sequence (λs, strunc s (spi X (λx, Y x)))
-- (λs, !postnikov_smap ∘ₛ strunc_change_int _ !succ_pred⁻¹)
-- -- parameters (k : ) (H : Π(x : X) (n : ), is_trunc (k + n) (Y x n))
-- end atiyah_hirzebruch

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@ -570,6 +570,9 @@ namespace smash
smash_iterate_psusp n A pbool ⬝e*
iterate_psusp_pequiv n (smash_pbool_pequiv A)
definition smash_pcircle (A : Type*) : A ∧ pcircle ≃* psusp A :=
smash_sphere A 1
definition sphere_smash_sphere (n m : ) : psphere n ∧ psphere m ≃* psphere (n+m) :=
smash_sphere (psphere n) m ⬝e*
iterate_psusp_pequiv m (psphere_pequiv_iterate_psusp n) ⬝e*

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@ -192,15 +192,14 @@ namespace pointed
psquare (pequiv_ap B p) (pequiv_ap C p) (f a) (f a') :=
begin induction p, exact phrfl end
definition pequiv_ap_natural2 {A : Type} (B C : A → Type*) {a a' : A} (p : a = a')
(f : Πa, B a →* C a) :
psquare (pequiv_ap B p) (pequiv_ap C p) (f a) (f a') :=
begin induction p, exact phrfl end
definition loop_pequiv_punit_of_is_set (X : Type*) [is_set X] : Ω X ≃* punit :=
pequiv_punit_of_is_contr _ (is_contr_of_inhabited_prop pt)
definition loop_punit : Ω punit ≃* punit :=
loop_pequiv_punit_of_is_set punit
definition phomotopy_of_is_contr [constructor] {X Y: Type*} (f g : X →* Y) [is_contr Y] :
f ~* g :=
phomotopy.mk (λa, !eq_of_is_contr) !eq_of_is_contr
end pointed

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@ -2,4 +2,4 @@ import core
open susp smash pointed wedge prod
definition susp_product (X Y : Type*) : ⅀ (X × Y) ≃* ⅀ X (⅀ Y ⅀ (X ∧ Y)) :=
sorry
sorry