Lecture 01 (09/26)
Introduction; Turing machines; Decision problems; Complexity classes;
L, NL, P, NP, PSPACE, EXP, etc.
Basic hierarchy theorems
Lecture 02 (10/01)
Reductions, completeness;
Boolean circuits & generic completeness: CVP, Circuit-SAT, SAT, Oracle-SAT
(Cor: NP subset of PSPACE)
Other examples of NP completeness
Lecture 03 (10/03)
NP-completeness, contd.
Fagin's theorem (statement only) and the importance of NP
Very hard optimization problems; Polynomial-time hierarchy
Lecture 04 (10/08)
Reducibility and Completeness for space-bounded classes:
1-GAP, GAP, Succinct-GAP, QBF
(Cor: NL subset of P, PSPACE subset of EXP)
Lecture 05 (10/10)
Savitch's theorem: NL subset of DSPACE[log^2 n]
(Cor: NPSPACE = PSPACE)
The Immerman--Szelepscenyi theorem: NL = coNL
Time permitting:
Counting problems; the classes #P and #L; #SAT and #STCON
Completeness of the Permanent and the Determinant, resp., for these classes
Lecture 06 (10/15)
The Boolean circuit model; parallel computation
P/poly, AC^0, NC^1, NC^2, NC, SC
Their relationship to L and NL:
NC^1 subset of L subset of NL subset of NC^2
Mention linear algebra
Lecture 07 (10/17)
Brief discussion of "abstract" vs. "concrete" complexity results
Parity not in AC^0; Hastad's switching lemma
The results of Kannan, Nepomnjascii, Fortnow, Fortnow--van Melkebeek
(eg., SAT not in DTISP[n polylog n, n^{0.99}]
State both, prove one set.
Lecture 08 (10/22)
Enter randomization: mention primality (yes!), zero-testing,
perfect matching, Frievalds, USTCON.
The classes RP, BPP, ZPP;
BPP subset of PH (Sipser's proof); Valiant--Vazirani;
Lecture 09 (10/24)
(Revisit) Counting complexity classes; the classes #P and PP
Toda's theorem
Lecture 10 (10/29)
USTCON - mention theorem of AKLLR; Nisan's pseudorandom generator
RL subset of SC
Lecture 11 (10/31)
Saks--Zhou: BPL subset of DSPACE[log^{3/2} n]
Lecture 12 (11/05)
Efficient proof-checking via randomness:
relaxations and restrictions (MA, PCP)
MA subset of PH (co-NP subset of MA implies PH collapses)
PCP and hardness of approximation (of clique)
Lecture 13 (11/07)
NP subset of PCP[poly, 1]
Lecture 14 (11/12)
NP subset of PCP[polylog, polylog]
Lecture 15 (11/14)
NP subset of PCP[log, polylog]
Lecture 16 (11/19)
Likely: No class due to FOCS
Unlikely: Composition of PCPs, complete NP = PCP[log n, 1] and
do a sketch of the low-degree tester in Lecture 17
Lecture 17 (11/21)
Composition of PCPs, complete NP = PCP[log n, 1]
Lecture 18 (11/26)
Interaction in proof-checking: AM, IP, Graph non-isomorphism
AM = IP; AM[c] = AM[2]
Lecture 19 (12/03)
IP = PSPACE;
Multi-prover protocols, Proof systems; MIP = NEXPTIME
Lecture 20 (12/05)
SZK; Graph isomorphism; SZK = IP with 1 bit (+ ugly restriction)