curl --request POST \
  --url https://api.fincept.in/quantlib/physics/ising/critical-temperature \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '{
  "J": 1
}'

{
  "success": true,
  "data": {
    "critical_temperature": 2.269,
    "coupling_constant": 1
  }
}

{
  "detail": "Invalid API key"
}

{
  "detail": "Insufficient credits. This endpoint requires 5 credits."
}

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>"
    }
  ]
}

quantlib-physics

Calculate 2D Ising Model Critical Temperature

Calculates the exact critical temperature for the 2D Ising model on a square lattice. At the critical temperature T_c, the system undergoes a second-order phase transition from ordered (ferromagnetic) to disordered (paramagnetic) phase. The critical temperature is given by Onsager’s exact solution.

Use Cases:

Identify phase transition thresholds in financial systems
Critical points for market regime changes
Systemic risk tipping points
Percolation and contagion thresholds
Universality class analysis

Formula (Onsager): T_c = 2J / [ln(1 + √2)] ≈ 2.269 J

Credits: 5 credits per request (Pro Tier) [Tier: ENTERPRISE, Credits: 10]

POST

quantlib

physics

ising

critical-temperature

curl --request POST \
  --url https://api.fincept.in/quantlib/physics/ising/critical-temperature \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '{
  "J": 1
}'

{
  "success": true,
  "data": {
    "critical_temperature": 2.269,
    "coupling_constant": 1
  }
}

{
  "detail": "Invalid API key"
}

{
  "detail": "Insufficient credits. This endpoint requires 5 credits."
}

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>"
    }
  ]
}

Authorizations

X-API-Key

string

header

required

API key for authentication. Get your key at https://api.fincept.in/auth/register

Body

application/json

number

default:1

Coupling constant (interaction strength)

Example:

1

Response

Critical temperature calculated successfully

success

boolean

Example:

true

data

object

Show child attributes

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Basic Tier (1 credit)

Standard Tier (2 credits)

Pro Tier (5 credits)

Enterprise Tier (10 credits)

Calculate 2D Ising Model Critical Temperature

Authorizations

Body

Response