Lost in an EFT? You are here! The path to You are here! the - - PowerPoint PPT Presentation
Lost in an EFT? You are here! The path to You are here! the - - PowerPoint PPT Presentation
Lost in an EFT? You are here! The path to You are here! the pagoda Current LHC no obvious exploration.. signposts so far What can we understand about the maze in general? A first glance at some deep underlying structure of EFTs
You are here!
The path to the pagoda You are here!
Current LHC exploration.. …no obvious signposts so far
What can we understand about the maze in general?
A first glance at some deep underlying structure of EFTs
Ongoing work to understand mathematical structure of quantum EFTs on general grounds
with Brian Henning, Xiaochuan Lu, and Hitoshi Murayama
The importance and ubiquity of EFTs has been understood for decades — remarkable that very basic questions about their structure are (were) unknown
M=SO(4) inv. M=SO(d) G linear G non-linear IR free EFTs invariant under M(spacetime)xG(gauge,global)
M=SO(4) inv. M=SO(d) G linear G non-linear IR free
Brian Henning, Xiaochuan Lu, TM, and Hitoshi Murayama, to appear
EFTs invariant under M(spacetime)xG(gauge,global)
M=SO(4) inv. M=SO(d) G linear G non-linear IR free
Mostly touch on this for this talk
EFTs invariant under M(spacetime)xG(gauge,global)
Practical problem
Redundancies between operators from equations of motion and integration by parts
L = X
i
ciOi
O1 ∼ O2 + dO3 O1 ∼ O2 + δS δφi O3 EOM IBP
EFT of a single real scalar field
4 7 10 16 25 39 61 98 155 254 410 687 1137 1933 3304 5691 9966 17456 30973 55133 98613 2 3 4 6 8 12 16 25 35 55 80 127 194 312 495 810 1316 2196 3624 6109 10213 1 1 1 2 2 3 3 5 6 9 11 17 22 34 47 74 106 169 256 412 643SOH4L SOH4L + EOM SOH4L + EOM + IBP
5 10 15 20 25 1 10 102 103 104 105 Mass Dimension
- No. of Operators
SOH4L SOH4L + EOM SOH4L + EOM + IBP
5 10 15 20 25 1 10 102 103 104 105 Mass Dimension
- No. of Operators
‘naive’=SO(∞) is interesting (but hard)
∂µ∂νφ ∂µ∂νφ φ2 ∂µφ ∂µ∂νφ ∂νφ φ ∂µφ ∂µφ ∂νφ ∂νφ
Graph theory:
?
It turns out the structure of an
- perator basis is controlled by
the conformal algebra Organize into irreps. of the conformal group — the basis is spanned by primary operators
Why the conformal algebra?
SU(2) toy: build ‘operators’ out of two spin 1/2 states + + + Spin A
- r
Spin B
- r
The ‘Lagrangian’ =
Why the conformal algebra?
SU(2) toy: build ‘operators’ out of two spin 1/2 states +
- 2 x 2 = 3 + 1
x = +
Why the conformal algebra?
x.. x..
φ ∂µφ ∂{µ∂ν}φ ∂{µ∂ν∂ρ}φ Fµν ∂ρFµν ψα ∂βψα ∂δ∂βψα ∂σ∂ρFµν R[ 3
2 ,( 1 2 ,0)]
R[2,(1,0)] = X
∆,j1,j2
c∆,j1,j2 O[∆,(j1,j2)] ∂µO[∆,(j1,j2)] . . . . . . . . . . . .
repr. = R[∆,(j1,j2)]
R[1,(0,0)]
Why the conformal algebra?
x.. x..
φ ∂µφ ∂{µ∂ν}φ ∂{µ∂ν∂ρ}φ Fµν ∂ρFµν ψα ∂βψα ∂δ∂βψα ∂σ∂ρFµν R[ 3
2 ,( 1 2 ,0)]
R[2,(1,0)]
repr. = R[∆,(j1,j2)]
= X
∆,j1,j2
c∆,j1,j2 O[∆,(j1,j2)] ∂µO[∆,(j1,j2)]
All total derivatives
. . . . . . . . . . . .
Keep only scalar primary
- perators
R[1,(0,0)]
Why the conformal algebra? We have an alternate picture in terms of scattering amplitudes EOM: on-shell particles IBP: momentum conservation
A recipe for constructing a Hilbert series for 4d phenomenological theories
Application to the SM
On this operator basis we defined a generating function — Hilbert series Evaluate to count the number of independent
- perators at a given mass dimension in the SM
Buchmuller, Wyler 1986 Grzadkowski et. al. 2010 Manohar et. al. 2013 Lehman, Martin 2014 dim 6, 1 gen. dim 6, 1 gen, corrected dim 6, Nf gen. dim 7, Nf gen. dim 8, 1 gen.
What a Hilbert series looks like
Hilbert series
H(D, Q, u, d, L, e, H, FL, ..)
= Z
SO(6)
Z
SU(3)×SU(2)×U(1)
PE(χQ, χu, χd, χL, χe, χH, χFL, ..)
What a Hilbert series looks like
Plethystic exponential: generate all possible operators
= Z
SO(6)
Z
SU(3)×SU(2)×U(1)
PE(χQ, χu, χd, χL, χe, χH, χFL, ..)
H(D, Q, u, d, L, e, H, FL, ..)
PE(χL) = exp ∞ X
r=1
Lr χ[ 3
2 ,( 1 2 ,0)](αr, βr, qr) χ2,SU(2)(yr)
!
e.g.
χR(g) = trR(g) χ2,SU(2)(g) = tr
- diag(eiθ, e−iθ)
- = y + y−1
Characters e.g.
hgh−1 = eiθaHa
What a Hilbert series looks like
Haar measures: project out scalar, gauge inv operators
e.g.
= Z
SO(6)
Z
SU(3)×SU(2)×U(1)
PE(χQ, χu, χd, χL, χe, χH, χFL, ..)
Z dµSU(2)(y) = I dy 2πi 1 y (1 − y2)(1 − y−2)
H(D, Q, u, d, L, e, H, FL, ..)
= I dα 2πi I dβ 2πi
- 1 − α22
1 − β22 4α3β3 I dx 2πi 1 x I dy 2πi
- 1 − y22
2y3 I dz1 2πi I dz2 2πi
- z2
1 − z2
2 (1 − z1z2)2 z1 − z2
2
2 6z5
1z5 2
H2L2
- y4 + y2 + 1
⇣ α2 + α2y4 +
- α2 + 1
2 y2⌘ α2y4 + (H†)2(L†)2
- y4 + y2 + 1
⇣ β2 + β2y4 +
- β2 + 1
2 y2⌘ β2y4
+ . . .
- = H2L2 + H† 2L† 2
Neutrino mass
HS(D, Q, u, d, L, e, H, FL, ..)
- dim 5
What a Hilbert series looks like
What a Hilbert series looks like
HS(D, Q, u, d, L, e, H, FL, ..)
- dim 6
b6 = H3H† 3 + u†Q†HH† 2 + 2Q2Q† 2 + Q† 3L† + Q3L + 2QQ†LL† + L2L† 2 + uQH2H† + 2uu†QQ† + uu†LL† + u2u† 2 + e†u†Q2 + e†L†H2H† + 2e†u†Q†L† + eLHH† 2 + euQ† 2 + 2euQL + ee†QQ† + ee†LL† + ee†uu† + e2e† 2 + d†Q†H2H† + 2d†u†Q† 2 + d†u†QL + d†e†u† 2 + d†eQ†L + dQHH† 2 + 2duQ2 + duQ†L† + de†QL† + deu2 + 2dd†QQ† + dd†LL† + 2dd†uu† + dd†ee† + d2d† 2 + u†Q†H†GR + d†Q†HGR + HH†G2
R + G3 R + uQHGL
+ dQH†GL + HH†G2
L + G3 L + u†Q†H†WR + e†L†HWR + d†Q†HWR + HH†W 2 R + W 3 R
+ uQHWL + eLH†WL + dQH†WL + HH†W 2
L + W 3 L + u†Q†H†BR + e†L†HBR
+ d†Q†HBR + HH†BRWR + HH†B2
R + uQHBL + eLH†BL + dQH†BL + HH†BLWL
+ HH†B2
L + 2QQ†HH†D + 2LL†HH†D + uu†HH†D + ee†HH†D + d†uH2D + du†H† 2D
+ dd†HH†D + 2H2H† 2D2 . (3.16)
First systematic procedure (one generation)
Counting in the SM EFT
2 30 560 11962 257378 5474170 84 993 15456 261485 4614554 12 1542 90456 3472266 175373592 7557369962 3045 44807 2092441 75577476 2795173575 5 6 7 8 9 10 11 12 13 14 15 1 10 100 1000 10000 100000 1000000 10000000 100000000 1000000000 10000000000Mass dimension
- No. of independent ops
Nf=1 Nf=3
Never have to count ops again….
Hilbert series for your theory
= Z
SO(6)
Z
gauge, global
PE(χψ1, χψ2, . . .) H(D, ψ1, ψ2, . . .)
Characters for the repr. of each field Gauge and global symmetries of the EFT
Explicit example of a particular maze…
Explicit example of a particular maze…
H(φ1, .., φN, t) = Z dµSO(d) 1 P(t; x)
N
Y
i=1
exp ∞ X
r=1
φi(1 − t2)P(t; x) !
in four dimensions
H(φ, t)|φ4 = φ4 1 (1 − t4)(1 − t6)
Explicit example of a particular maze…
H(φ1, .., φN, t) = Z dµSO(d) 1 P(t; x)
N
Y
i=1
exp ∞ X
r=1
φi(1 − t2)P(t; x) !
in four dimensions
H(φ, t)|φ4 = φ4 1 (1 − t4)(1 − t6)
n=4
Explicit example of a particular maze…
H(φ1, .., φN, t) = Z dµSO(d) 1 P(t; x)
N
Y
i=1
exp ∞ X
r=1
φi(1 − t2)P(t; x) !
in four dimensions
n=4 n=5 …
H(φ, t)|φ5 = φ5 t28 + t22 + t16 + t14 + t12 + t8 − t6 + t4 − t2 + 1 (1 − t2)(1 − t6)(1 − t8)(1 − t10)(1 − t12)
Explicit example of a particular maze…
H(φ, t)|φ4 = φ4 1 (1 − t4)(1 − t6)
n=4 n=5 …
H(φ1, .., φN, t) = Z dµSO(d) 1 P(t; x)
N
Y
i=1
exp ∞ X
r=1
φi(1 − t2)P(t; x) !
in four dimensions
fixed powers of t …
Explicit example of a particular maze…
H(φ1, φ2, t) = 1 (1 − φ1)(1 − φ2)(1 − tφ1φ2)
in one dimension
Explicit example of a particular maze…
H(φ1, φ2, t) = 1 (1 − φ1)(1 − φ2)(1 − tφ1φ2)
in one dimension
H(φ1, φ2, φ3, t) = 1 − tφ1φ2φ3 (1 − φ1)(1 − φ2)(1 − φ3)(1 − tφ1φ2)(1 − tφ1φ3)(1 − tφ2φ3)
Explicit example of a particular maze…
H(φ1, φ2, t) = 1 (1 − φ1)(1 − φ2)(1 − tφ1φ2)
in one dimension
H(φ1, φ2, φ3, t) = 1 − tφ1φ2φ3 (1 − φ1)(1 − φ2)(1 − φ3)(1 − tφ1φ2)(1 − tφ1φ3)(1 − tφ2φ3)
HN+1 (¯ u0, ¯ u1, · · · , ¯ uN+1) =
- |x|=1
dx 2πi 1 xHN (¯ u0, · · · , ¯ uN−1, x) H2
- x−1, ¯
uN, ¯ uN+1
- .
u0 u1 u2
u1 u0 u2 u3 x x−1 → u1 u0 u2 u3
Flavour recursion
Explicit example of a particular maze…
H(φ1, φ2, φ3, t) = 1 − tφ1φ2φ3 (1 − φ1)(1 − φ2)(1 − φ3)(1 − tφ1φ2)(1 − tφ1φ3)(1 − tφ2φ3)
Information/structure not seen at any perturbative order This object contains physics — counts number of independent ‘measurements’
Some dreaming…
HSM = ***All order result???***
How best to interpret the information? Can it provide hints to possible paths? Non-renormalization info?
- J. Elias-Miro, J. R. Espinosa and A. Pomarol
- C. Cheung and C.-H. Shen
- R. Alonso, E. E. Jenkins, and A. V. Manohar
…
Who knows what we might discover if we go far enough…
Extra slides
n=3 n=4 n=… n=5
L = X
n,k
cn,kφn∂k
Operator Basis
C4,4 C4,6 C4,8 C4,10 C4,12 C4,12
1 2
C5,4 C5,6 C5,8 C5,8
1 2
Searching for theories ? ? ? ? ? ?
L = X
n,k
cn,kφn∂k
C4,4 C4,6 C4,8 C4,10 C4,12 C4,12
1 2
C5,4 C5,6 C5,8 C5,8
1 2
Searching for theories ? ? ? ? ? Look for enhanced soft limits in amplitudes
Cheung, Kampf, Novotny, Trnka 2015 Cachazo, Cha, Mizera 2016
Tom Melia SLAC Theory Seminar 29th Jan ‘16
SU(2)
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Warm-up with SU(2)
- Characters
- Plethystic Exponential
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Warm-up with SU(2)
Characters
- Plethystic Exponential
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Characters
χR(g) = TrR(g) g ∈ G R G
Repr
- f
= TrR(hgh−1) hgh−1 = eiθaHa
where can always write
Cartan generators
χR(x1, . . . , xr)
Rank of G (# Cartan)
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Characters of SU(2)
Spin j irreps. labelled by their dimensions (2j+1)
Rank 1, Cartan generator T3
eiθT3 = diag(eijθ, ei(j−1)θ, . . . , ei(−j)θ)
y = eiθ
χ(2j+1) = Tr(eiθT3) = y2j + y2j−2 + . . . + y−2j
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Characters of SU(2)
- tensor products, decomposition
2 × 2 = 3 + 1
χ2χ2 = χ3 + χ1
(y + y−1)(y + y−1) = (y2 + 1 + y−2) + 1
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Characters of SU(2)
- character orthogonality
Z dµ({xr}) χ∗
i ({xr})χj({xr}) = δij
Z
G
dg χ∗
i (g)χj(g) = δij
For SU(2)
Z dµSU(2) = I
|y|=1
dy 2πi (1 − y2)(1 − y−2) y
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Warm-up with SU(2)
Plethystic Exponential
- Characters
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Plethystic Exponential
- generating function for sym tensor products
1 detR(1 − ug) = X
n
unsymnχR
1 detR(1 − ug) = exp [−TrR log(1 − ug)] = exp " ∞ X
n=1
1 nunTrR(gn) #
= exp " ∞ X
n=1
1 nunχ(xn
1, . . . , xn r )
# = PE[uχR]
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
- for SU(2)
1 det2(1 − ug) = 1 det ✓ 1 1 ◆ − ✓ uy u/y ◆ = 1 (1 − uy)(1 − u/y) = 1 + (y + y−1)u + (y2 + 1 + y−2)u2 + (y3 + y + y−1 + y−3)u3 + . . .
Plethystic Exponential
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
- for SU(2)
1 det2(1 − ug) = 1 det ✓ 1 1 ◆ − ✓ uy u/y ◆ = 1 (1 − uy)(1 − u/y) = 1 + (y + y−1)u + (y2 + 1 + y−2)u2 + (y3 + y + y−1 + y−3)u3 + . . .
1 2(χ2(y2) + χ2(y)2)
sym2χ2 =
Plethystic Exponential
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
- for SU(2)
1 det2(1 − ug) = 1 det ✓ 1 1 ◆ − ✓ uy u/y ◆ = 1 (1 − uy)(1 − u/y) = 1 + (y + y−1)u + (y2 + 1 + y−2)u2 + (y3 + y + y−1 + y−3)u3 + . . .
1 2(χ2(y2) + χ2(y)2) = χ3(y)
2 2 = 3
sym2χ2 =
Plethystic Exponential
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
SO(d+2,C)
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Characters for SO(d+2,C)
χ[∆,l](q, x1, . . . , xr) = q∆ P(q; x)χl(x)
- Irrep. of conformal group
R[∆,l] = Φl ∂µΦl ∂{µ1∂µ2}Φl . . .
“Character formulae and partition functions in higher dimensional conformal field theory” arXiv:hep-th/0508031
- F. A. Dolan
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
Characters for SO(d+2,C)
χ[∆,l](q, x1, . . . , xr) = q∆ P(q; x)χl(x) R[∆,l] = Φl ∂µΦl ∂{µ1∂µ2}Φl . . .
P(q; x) = 1 det⇤(1 − qg) = 1 Qr
i=1(1 − qxi)(1 − q/xi)
1 1 − qδd,odd
Irrep of SO(d)
- Irrep. of conformal group
l = (l1, . . . , lr)
spin scaling dim
r = d 2 ⌫
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Tom Melia SLAC Theory Seminar 29th Jan ‘16
counting in Nf
# Dim 5 = ✓ Nf + N 2
f◆ # Dim 6 = ✓ 15 + 135 4 N 2
f + 12N 3
f + 1074 N 4
f◆ + ✓2 3N 2
f + N 3 f + 193 N 4
f◆ # Dim 7 = ✓ 2Nf + 26 3 N 2
f + N 3 f + 313 N 4
f◆ + ✓ N 3
f + 7N 4 f◆ # Dim 8 = ✓ 89 + 789 2 N 2
f + 8232 N 4
f◆ + ✓2 3N 2
f + N 3 f + 2893 N 4
f◆ # Dim 9 = ✓ 9Nf + 83N 2
f + 4912N 3
f + 258712 N 4
f − 112N 5
f + 43712 N 6
f◆ + ✓ − 4 3N 2
f + 293 N 3
f + 4633 N 4
f + 13N 5
f + 41N 6 f◆ + ✓1 4N 2
f + 6124N 3
f + 2924N 4
f + 1124N 5
f + 8524N 6
f◆ # Dim 10 = ✓ 530 + 53927 12 N 2
f − 172 N 3
f + 8212712 N 4
f − 6N 5 f + 37763 N 6
f◆ + ✓ − 10 9 N 2
f + 1553 N 3
f + 3016918 N 4
f + 373 N 5
f + 1089118 N 6
f◆ # Dim 11 = ✓ 18Nf + 2812 3 N 2
f − 1523 N 3
f + 116893 N 4
f − 583 N 5
f + 55513 N 6
f◆ + ✓ − 2N 2
f + 4433 N 3
f + 88303 N 4
f + 3523 N 5
f + 58553 N 6
f◆ + ✓3 4N 2
f + 30724 N 3
f + 724N 4
f + 19724 N 5
f + 359924 N 6
f◆ # Dim 12 = ✓ 4481 + 1 2Nf + 613247 12 N 2
f − 538124 N 3
f + 784699172 N 4
f − 892724 N 5
f + 318170972 N 6
f − 356 N 7
f + 5094736 N 8
f◆ + ✓28 9 N 2
f + 19543 N 3
f + 27779N 4 f + 682312 N 5
f + 1314296 N 6
f + 16912 N 7
f + 1780318 N 8
f◆ + ✓11 24N 3
f + 1483144 N 4
f + 1912N 5
f + 14972 N 6
f + 4724N 7
f + 4555144 N 8
f◆
+ full Hilbert series provided
Tom Melia SLAC Theory Seminar 29th Jan ‘16
counting in Nf
# Dim 5 = ✓ Nf + N 2
f◆ # Dim 6 = ✓ 15 + 135 4 N 2
f + 12N 3
f + 1074 N 4
f◆ + ✓2 3N 2
f + N 3 f + 193 N 4
f◆ # Dim 7 = ✓ 2Nf + 26 3 N 2
f + N 3 f + 313 N 4
f◆ + ✓ N 3
f + 7N 4 f◆ # Dim 8 = ✓ 89 + 789 2 N 2
f + 8232 N 4
f◆ + ✓2 3N 2
f + N 3 f + 2893 N 4
f◆ # Dim 9 = ✓ 9Nf + 83N 2
f + 4912N 3
f + 258712 N 4
f − 112N 5
f + 43712 N 6
f◆ + ✓ − 4 3N 2
f + 293 N 3
f + 4633 N 4
f + 13N 5
f + 41N 6 f◆ + ✓1 4N 2
f + 6124N 3
f + 2924N 4
f + 1124N 5
f + 8524N 6
f◆ # Dim 10 = ✓ 530 + 53927 12 N 2
f − 172 N 3
f + 8212712 N 4
f − 6N 5 f + 37763 N 6
f◆ + ✓ − 10 9 N 2
f + 1553 N 3
f + 3016918 N 4
f + 373 N 5
f + 1089118 N 6
f◆ # Dim 11 = ✓ 18Nf + 2812 3 N 2
f − 1523 N 3
f + 116893 N 4
f − 583 N 5
f + 55513 N 6
f◆ + ✓ − 2N 2
f + 4433 N 3
f + 88303 N 4
f + 3523 N 5
f + 58553 N 6
f◆ + ✓3 4N 2
f + 30724 N 3
f + 724N 4
f + 19724 N 5
f + 359924 N 6
f◆ # Dim 12 = ✓ 4481 + 1 2Nf + 613247 12 N 2
f − 538124 N 3
f + 784699172 N 4
f − 892724 N 5
f + 318170972 N 6
f − 356 N 7
f + 5094736 N 8
f◆ + ✓28 9 N 2
f + 19543 N 3
f + 27779N 4 f + 682312 N 5
f + 1314296 N 6
f + 16912 N 7
f + 1780318 N 8
f◆ + ✓11 24N 3
f + 1483144 N 4
f + 1912N 5
f + 14972 N 6
f + 4724N 7
f + 4555144 N 8
f◆
some large primes… + full Hilbert series provided
Tom Melia SLAC Theory Seminar 29th Jan ‘16
some larger primes…
# Dim 13 = −109Nf + 159296 15 N 2
f + 3206390 N 3
f + 514075645 N 4
f + 7825372 N 5
f + 42846881360 N 6
f + 68723360 N 7
f+ 4311047 360 N 8
f# Dim 14 = 40715 − 2Nf + 105860297 180 N 2
f + 8975918 N 3
f + 1513774187720 N 4
f + 6397172 N 5
f + 299553293180 N 6
f− 117979 72 N 7
f + 51562231240 N 8
f# Dim 15 = −2427Nf + 21647887 180 N 2
f − 11461920 N 3
f + 387130705216 N 4
f − 100262691440 N 5
f + 456200951160 N 6
f− 3717991 720 N 7
f + 103741331144 N 8
f − 5349411440 N 9
f + 9163865864 N 10
fcounting in Nf
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