Handle friendship seminar 2020 since 2013

Place:University of Tokyo (Komaba campus) or online
japanese version

If you want to attend this zoom seminar, please register here.
If you register there, I send the Zoom URL to your email address.

2020 Autumn

• The tenth break 1/14 (Thur.) (Zoom meeting)
  Yuta Nozaki 10:00-12:30 (GMT +09:00)
  [Title] Abelian quotients of the Y-filtration on the homology cylinders and clasper surgery
  [Abstract]
  
  
• The tenth break 12/10 (Thur.) (Zoom meeting)
  Oğuz Şavk 19:10-20:10 (GMT +09:00)
  [Title] Brieskorn spheres, homology cobordism and homology balls
  [Abstract] A classical question in low-dimensional topology asks which homology 3-spheres bound homology 4-balls. This question is fairly addressed to Brieskorn spheres Σ(p,q,r), which are defined to be links of singularities x^p+y^q+z^r=0. Over the years, Brieskorn spheres also have been the main objects for the understanding of the algebraic structure of the integral homology cobordism group.
  
  In this talk, we will present several families of Brieskorn spheres which do or do not bound integral and rational homology balls via Ozsváth-Szabó d-invariant, involutive Heegaard Floer homology, and Kirby calculus. Also, we will investigate their positions in both integral and rational homology cobordism groups.
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2020 Spring

• The nineth break 8/20 (Thu.) (Zoom meeting)
  Masaki Taniguchi 10:00-12:30 (GMT +09:00)
  [Title] Local equivalence on Instanton Floer theory VII
  [Abstract]
  
• The eighth break 8/6 (Thu.) (Zoom meeting)
  Masaki Taniguchi 10:00-12:30 (GMT +09:00)
  [Title] Local equivalence on Instanton Floer theory VI
  [Abstract]
  
• The seventh break 7/9 (Thu.) (Zoom meeting)
  Masaki Taniguchi 10:00-12:30 (GMT +09:00)
  [Title] Local equivalence on Instanton Floer theory V
  [Abstract]
  
• The sixth break 6/25 (Thu.) (Zoom meeting)
  Tadayuki Watanabe 10:00-12:30 (GMT +09:00)
  [Title] Theta-graph and diffeomorphisms of some 4-manifolds
  [Abstract]
  
• The fifth break 6/19 (Fri.) (Zoom meeting)
  Masaki Taniguchi 10:00-12:30 (GMT +09:00)
  [Title] Local equivalence on Instanton Floer theory IV
  [Abstract]
  
• The fourth break 6/11 (Thu.) (Zoom meeting)
  Masaki Taniguchi 10:00-12:30 (GMT +09:00)
  [Title] Local equivalence on Instanton Floer theory III
  [Abstract]
  
• The third break 5/21 (Thu.) (Zoom meeting)
  Masaki Taniguchi 10:00-12:30 (GMT +09:00)
  [Title] Local equivalence on Instanton Floer theory II
  [Abstract]
  
• The second break 4/15 (Wed.) (Zoom meeting)
  Masaki Taniguchi 10:00-12:30
  [Title] Local equivalence on Instanton Floer theory I
  [Abstract]
  
  
• The first break 4/10 (Fri.) (Zoom meeting)
  Motoo Tange 10:00-12:30
  [Title] Third term of lens surgery polynomial
  [Abstract]
  For a Laurent polynomial Δ(t), if it is the Alexander polynomial of lens space knot K in S³, we say that Δ(t) is a lens surgery polynomial. What condition does a lens surgery polynomial have? This is the main question here. By Ozsvath and Szabo it is well-known that any lens surgery polynomial is flat and alternating. The "flat" means that any coefficients are ±1 or 0. The "alternating" means that any non-zero coefficients are alternating. It is wel-known that the top term and the second term of any lens surgery polynomial are 1 and -1 respectively. Teragaito conjectured that if the third term is non-zero, then the polynomial is the same as (2,2g+1)-torus knot polynomial. Here I proved the question is affirmative.