The Quadrillion F-Theory Standard Models (QSMs)
A yet more special instance of literature models are the Quadrillion F-theory Standard Models (F-theory QSMs) [CHLLT19]. Those hypersurface models come in 708 different families.
The base geometry of an F-theory QSM is obtained from triangulating one of 708 reflexive 3-dimensional polytopes. The models, whose bases are obtained from triangulations of the same polytope form a family. The following information on the polytope in question and its triangulations is available within our database:
vertices
— Methodvertices(m::AbstractFTheoryModel)
This method returns the vertices of the polytope the the base of the F-theory QSM is build from. Note that those vertices are normalized according to the Polymake standard to rational numbers.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> vertices(qsm_model)
4-element Vector{Vector{QQFieldElem}}:
[-1, -1, -1]
[1, -1//2, -1//2]
[-1, 2, -1]
[-1, -1, 5]
This function is part of the experimental code in Oscar. Please read here for more details.
polytope_index
— Methodpolytope_index(m::AbstractFTheoryModel)
Of the 3-dimensional reflexive polytope that the base of this F-theory model is build from, this method returns the index within the Kreuzer-Skarke list.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> polytope_index(qsm_model)
4
This function is part of the experimental code in Oscar. Please read here for more details.
has_quick_triangulation
— Methodhas_quick_triangulation(m::AbstractFTheoryModel)
For a 3-dimensional reflexive polytope in the Kreuzer-Skarke list, the list of full (sometimes also called fine), regular, star triangulations can be extremely large. Consequently, one may wonder if the triangulations can be enumerated in a somewhat reasonable time (say 5 minutes on a personal computer). This method tries to provide an answer to this. It returns true
if one should expect a timely response to the attempt to enumerate all (full, regular, star) triangulations. Otherwise, this method returns false
.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> has_quick_triangulation(qsm_model)
true
This function is part of the experimental code in Oscar. Please read here for more details.
max_lattice_pts_in_facet
— Methodmax_lattice_pts_in_facet(m::AbstractFTheoryModel)
In order to enumerate the number of full, regular, star triangulations of a 3-dimensional reflexive polytope, it is possible to first find the corresponding triangulations of all facets of the polytope [HT17]. A first indication for the complexity of this triangulation task is the maximum number of lattice points in a facet of the polytope in question. This method returns this maximal number of lattice points.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> max_lattice_pts_in_facet(qsm_model)
16
This function is part of the experimental code in Oscar. Please read here for more details.
estimated_number_of_triangulations
— Methodestimated_number_of_triangulations(m::AbstractFTheoryModel)
This method returns an estimate for the number of full, regular, star triangulations of the 3-dimensional reflexive polytope, those triangulations define the possible base spaces of the F-theory QSM in question.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> estimated_number_of_triangulations(qsm_model)
212533333333
This function is part of the experimental code in Oscar. Please read here for more details.
Beyond the polytope and its triangulations, a number of other integers are of key importance. The following are supported in our database.
kbar3
— Methodkbar3(m::AbstractFTheoryModel)
Let Kbar denote the anticanonical class of the 3-dimensional base space of the F-theory QSM. Of ample importance is the triple intersection number of Kbar, i.e. Kbar * Kbar * Kbar. This method returns this intersection number.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> kbar3(qsm_model)
6
This function is part of the experimental code in Oscar. Please read here for more details.
hodge_h11
— Methodhodge_h11(m::AbstractFTheoryModel)
This methods return the Hodge number h11 of the elliptically fibered 4-fold that defined the F-theory QSM in question.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> hodge_h11(qsm_model)
31
This function is part of the experimental code in Oscar. Please read here for more details.
hodge_h12
— Methodhodge_h12(m::AbstractFTheoryModel)
This methods return the Hodge number h12 of the elliptically fibered 4-fold that defined the F-theory QSM in question.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> hodge_h12(qsm_model)
10
This function is part of the experimental code in Oscar. Please read here for more details.
hodge_h13
— Methodhodge_h13(m::AbstractFTheoryModel)
This methods return the Hodge number h13 of the elliptically fibered 4-fold that defined the F-theory QSM in question.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> hodge_h13(qsm_model)
34
This function is part of the experimental code in Oscar. Please read here for more details.
hodge_h22
— Methodhodge_h22(m::AbstractFTheoryModel)
This methods return the Hodge number h22 of the elliptically fibered 4-fold that defined the F-theory QSM in question.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> hodge_h22(qsm_model)
284
This function is part of the experimental code in Oscar. Please read here for more details.
More recently, a research program estimated the exact massless spectra of the F-theory QSMs (cf. [Bie24]). These studies require yet more information about the F-theory QSM geometries, which are supported by our database.
First, recall that (currently), the base of an F-theory QSM is a 3-dimensional toric variety B3. Let s in H^0(B3, Kbar_B3), then V(s) is a K3-surface. Moreover, let xi be the coordinates of the Cox ring of B3. Then V(xi) is a divisor in B3. Consequently, Ci = V(xi) cap V(s) is a divisor in the K3-surface V(s). For the root bundle counting program, these curves Ci are of ample importance (cf. [Bie24]). We support the following information on these curves:
genera_of_ci_curves
— Methodgenera_of_ci_curves(m::AbstractFTheoryModel)
This methods return the genera of the Ci curves. Recall that Ci = V(xi, s), where xi is a homogeneous coordinate of the 3-dimensional toric base space B3 of the QSM hypersurface model in question, and s is a generic section of the anticanonical bundle of B3. Consequently, we may use the coordinates xi as labels for the curves Ci.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> keys_list = collect(keys(genera_of_ci_curves(qsm_model)));
julia> my_key = only(filter(k -> string(k) == "x7", keys_list))
x7
julia> genera_of_ci_curves(qsm_model)[my_key]
0
This function is part of the experimental code in Oscar. Please read here for more details.
degrees_of_kbar_restrictions_to_ci_curves
— Methoddegrees_of_kbar_restrictions_to_ci_curves(m::AbstractFTheoryModel)
The anticanonical divisor of the 3-dimensional toric base space B3 of the QSM hypersurface model in question can be restricted to the Ci curves. The result of this operation is a line bundle. This method returns the degree of this line bundle for every Ci curve.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> keys_list = collect(keys(degrees_of_kbar_restrictions_to_ci_curves(qsm_model)));
julia> my_key = only(filter(k -> string(k) == "x7", keys_list))
x7
julia> degrees_of_kbar_restrictions_to_ci_curves(qsm_model)[my_key]
0
This function is part of the experimental code in Oscar. Please read here for more details.
topological_intersection_numbers_among_ci_curves
— Methodtopological_intersection_numbers_among_ci_curves(m::AbstractFTheoryModel)
The topological intersection numbers among Ci curves are also of ample importance. This method returns those intersection numbers in the form of a matrix.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> n_rows(topological_intersection_numbers_among_ci_curves(qsm_model))
29
julia> n_columns(topological_intersection_numbers_among_ci_curves(qsm_model))
29
This function is part of the experimental code in Oscar. Please read here for more details.
indices_of_trivial_ci_curves
— Methodindices_of_trivial_ci_curves(m::AbstractFTheoryModel)
Some of the Ci curves are trivial, in that V(xi, s) is the empty set. This method returns the vector of all indices of trivial Ci curves. That is, should V(x23, s) be the empty set, then 23 will be included in the returned list.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> indices_of_trivial_ci_curves(qsm_model)
10-element Vector{Int64}:
23
22
18
19
20
26
10
11
12
15
This function is part of the experimental code in Oscar. Please read here for more details.
topological_intersection_numbers_among_nontrivial_ci_curves
— Methodtopological_intersection_numbers_among_nontrivial_ci_curves(m::AbstractFTheoryModel)
The topological intersection numbers among the non-trivial Ci curves are used frequently. This method returns those intersection numbers in the form of a matrix.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> n_rows(topological_intersection_numbers_among_nontrivial_ci_curves(qsm_model))
19
julia> n_columns(topological_intersection_numbers_among_nontrivial_ci_curves(qsm_model))
19
This function is part of the experimental code in Oscar. Please read here for more details.
The collection of the Ci-curves form a nodal curve. To every nodal curve one can associate a (dual) graph. In this graph, every irreducible component of the nodal curve becomes a node/vertex of the dual graph, and every nodal singularity of the nodal curve turns into an edge of the dual graph. In the case at hand, this is rather simple.
The Ci-curves turn into the irreducible components of the nodel curve. Certainly, we only need to focus on the non-trivial Ci-curves. A non-trivial Ci-curve can split into multiple irreducible components. This is taken into account when the nodes/vertices of the dual graph are constructed.
The topological intersection numbers among the Ci-curves (or rather, their irreducible components) tells us how many nodal singularities link the Ci-curves (or rather, their irreducible components) in question. Hence, if the topological intersection numbers is zero, there is no edge between the corresponding nodes. Otherwise, if the topological intersection number is positive - say n -, then there are exactly n edges between the nodes in question.
The following functions access/create the so-obtained dual graph:
dual_graph
— Methoddual_graph(m::AbstractFTheoryModel)
This method returns the dual graph of the QSM model in question. Note that no labels are (currently) attached to the vertices/nodes or edges. To understand/read this graph correctly, please use the methods listed below.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> dual_graph(qsm_model)
Undirected graph with 21 nodes and the following edges:
(5, 1)(6, 5)(7, 6)(8, 7)(9, 4)(9, 8)(10, 1)(11, 4)(12, 3)(12, 10)(13, 3)(13, 11)(14, 1)(15, 4)(16, 3)(17, 3)(18, 2)(18, 14)(19, 2)(19, 15)(20, 2)(20, 16)(21, 2)(21, 17)
This function is part of the experimental code in Oscar. Please read here for more details.
This function is part of the experimental code in Oscar. Please read here for more details.
components_of_dual_graph
— Methodcomponents_of_dual_graph(m::AbstractFTheoryModel)
This method returns a vector with labels for each node/vertex of the dual graph of the QSM model in question. Those labels allow to understand the geometric origin of the node/vertex.
Specifically, recall that those nodes are associated to the Ci-curves, which are in turn given by Ci = V(xi, s). xi is a homogeneous coordinate of the 3-dimensional toric base space B3 of the QSM in question, and s is a generic section of the anticanonical bundle of B3.
Only non-trivial Ci = V(xi, s) correspond to vertices/nodes of the dual graph.
If Ci = V(xi, s) is irreducible and corresponds to the k-th component, then the label "Ci" appears at position k of the vector returned by this method. However, if Ci = V(xi, s) is reducible, then we introduce the labels Ci-0, Ci-1, Ci-2 etc. for those irreducible components of Ci. If Ci-0 corresponds to the k-th components of the dual graph, then the label "Ci-0" appears at position k of the vector returned by this method.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> components_of_dual_graph(qsm_model)
21-element Vector{String}:
"C0"
"C1"
"C2"
"C3"
"C4"
"C5"
"C6"
"C7"
"C8"
"C9"
⋮
"C16"
"C17"
"C21"
"C24-0"
"C24-1"
"C25"
"C27"
"C28-0"
"C28-1"
This function is part of the experimental code in Oscar. Please read here for more details.
degrees_of_kbar_restrictions_to_components_of_dual_graph
— Methoddegrees_of_kbar_restrictions_to_components_of_dual_graph(m::AbstractFTheoryModel)
The anticanonical bundle of the toric 3-dimensional base space of the F-theory QSM in question can be restricted to the (geometric counterparts of the) nodes/vertices of the dual graph. The result is a line bundle for each node/vertex. This method returns a vector with the degrees of these line bundles.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> degrees_of_kbar_restrictions_to_components_of_dual_graph(qsm_model)["C28-1"]
0
This function is part of the experimental code in Oscar. Please read here for more details.
genera_of_components_of_dual_graph
— Methodgenera_of_components_of_dual_graph(m::AbstractFTheoryModel)
This methods returns a vector with the genera of the (geometric counterparts of the) nodes/vertices of the dual graph.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> genera_of_components_of_dual_graph(qsm_model)["C28-1"]
0
This function is part of the experimental code in Oscar. Please read here for more details.
The dual graph is essential in counting root bundles (cf. [BCL21]). It turns out, that one can simplify this graph so that the computations at hand can be conducted on a simpler graph instead. The following functionality exists to access this simplified dual graph.
simplified_dual_graph
— Methodsimplified_dual_graph(m::AbstractFTheoryModel)
This method returns the simplified dual graph of the QSM model in question. Note that no labels are (currently) attached to the vertices/nodes or edges. To understand/read this graph correctly, please use the methods listed below.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> simplified_dual_graph(qsm_model)
Undirected graph with 4 nodes and the following edges:
(2, 1)(3, 1)(3, 2)(4, 1)(4, 2)(4, 3)
This function is part of the experimental code in Oscar. Please read here for more details.
components_of_simplified_dual_graph
— Methodcomponents_of_simplified_dual_graph(m::AbstractFTheoryModel)
This method returns a vector with labels for each node/vertex of the simplified dual graph. Otherwise, works identical to components_of_dual_graph(m::AbstractFTheoryModel)
.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> components_of_simplified_dual_graph(qsm_model)
4-element Vector{String}:
"C0"
"C1"
"C2"
"C3"
This function is part of the experimental code in Oscar. Please read here for more details.
degrees_of_kbar_restrictions_to_components_of_simplified_dual_graph
— Methoddegrees_of_kbar_restrictions_to_components_of_simplified_dual_graph(m::AbstractFTheoryModel)
Same as degrees_of_kbar_restrictions_to_components_of_dual_graph(m::AbstractFTheoryModel)
, but for the simplified dual graph.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> degrees_of_kbar_restrictions_to_components_of_simplified_dual_graph(qsm_model)["C2"]
2
This function is part of the experimental code in Oscar. Please read here for more details.
genera_of_components_of_simplified_dual_graph
— Methodgenera_of_components_of_simplified_dual_graph(m::AbstractFTheoryModel)
This methods returns a vector with the genera of the (geometric counterparts of the) nodes/vertices of the dual graph.
Examples
julia> qsm_model = literature_model(arxiv_id = "1903.00009", model_parameters = Dict("k" => 4))
Hypersurface model over a concrete base
julia> genera_of_components_of_simplified_dual_graph(qsm_model)["C2"]
0
This function is part of the experimental code in Oscar. Please read here for more details.