diff --git a/imagine/__init__.py b/imagine/__init__.py
index 23f5d894c618883893fca8da970e306d190f1cd1..8cf04f1d75096c09e85a5258ad4e41c1402bc8dd 100644
--- a/imagine/__init__.py
+++ b/imagine/__init__.py
@@ -6,6 +6,8 @@ from magnetic_fields import *
 from observers import *
 from priors import *
 
+from pymultinest import pymultinest
+
 from pipeline import Pipeline
 
 import nifty
diff --git a/imagine/carrier_mapper.py b/imagine/carrier_mapper.py
index 55e632a5333cee1f697bbc0c27e549b8ee8acd90..9f97563ea77cf46562e93ac7d664f2e166b0286a 100644
--- a/imagine/carrier_mapper.py
+++ b/imagine/carrier_mapper.py
@@ -3,7 +3,7 @@
 import numpy as np
 
 
-def carrier_mapper(x, a=-np.inf, m=0, b=np.inf):
+def infinity_mapper(x, a=-np.inf, m=0, b=np.inf):
     """
     Maps x from [-inf, inf] into the interval [a, b], where x=0 -> m
     """
@@ -31,3 +31,11 @@ def carrier_mapper(x, a=-np.inf, m=0, b=np.inf):
     # strech y to the interval [a,b]
     y = y*(b-a) + a
     return y
+
+
+def unity_mapper(x, a=0, b=1):
+    """
+    Maps x from [0, 1] into the interval [a, b]
+    """
+    # rescale and shift
+    return x * (b-a) + a
diff --git a/imagine/magnetic_fields/magnetic_field/magnetic_field_factory.py b/imagine/magnetic_fields/magnetic_field/magnetic_field_factory.py
index cdedf7118f516b65971c4b5060bf384d78331c73..ebcb145c64bc2a215fe514fd77d439fd4f76bc6a 100644
--- a/imagine/magnetic_fields/magnetic_field/magnetic_field_factory.py
+++ b/imagine/magnetic_fields/magnetic_field/magnetic_field_factory.py
@@ -4,7 +4,7 @@ import numpy as np
 
 from keepers import Loggable
 
-from imagine.carrier_mapper import carrier_mapper
+from imagine.carrier_mapper import unity_mapper
 
 from nifty import FieldArray, RGSpace
 
@@ -96,10 +96,13 @@ class MagneticFieldFactory(Loggable, object):
         for variable_name in variables:
             if variable_name in self.variable_to_parameter_mappings:
                 mapping = self.variable_to_parameter_mappings[variable_name]
-                mapped_variable = carrier_mapper(variables[variable_name],
-                                                 a=mapping[0],
-                                                 m=mapping[1],
-                                                 b=mapping[2])
+                mapped_variable = unity_mapper(variables[variable_name],
+                                               a=mapping[0],
+                                               b=mapping[2])
+#                mapped_variable = carrier_mapper(variables[variable_name],
+#                                                 a=mapping[0],
+#                                                 m=mapping[1],
+#                                                 b=mapping[2])
             else:
                 mapped_variable = np.float(variables[variable_name])
             parameter_dict[variable_name] = mapped_variable
diff --git a/imagine/pymultinest/__init__.py b/imagine/pymultinest/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..199a3821ac4ca9c24c88ae27de895edbd21dc329
--- /dev/null
+++ b/imagine/pymultinest/__init__.py
@@ -0,0 +1,3 @@
+# -*- coding: utf-8 -*-
+
+from pymultinest import pymultinest
diff --git a/imagine/pymultinest/mpi4py_shadow.py b/imagine/pymultinest/mpi4py_shadow.py
new file mode 100644
index 0000000000000000000000000000000000000000..25fe49c6ac3f0b5ec16e8be03a43a4eda5c1f265
--- /dev/null
+++ b/imagine/pymultinest/mpi4py_shadow.py
@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+
+
+class _MPI(object):
+    def __init__(self):
+        self.COMM_WORLD = _COMM_WORLD()
+
+
+class _COMM_WORLD(object):
+    def Get_size(self):
+        return 1
+
+MPI = _MPI()
diff --git a/imagine/pymultinest/pymultinest.py b/imagine/pymultinest/pymultinest.py
new file mode 100644
index 0000000000000000000000000000000000000000..a7e7f850be17ad1cb71ae157e2a472b49957d55c
--- /dev/null
+++ b/imagine/pymultinest/pymultinest.py
@@ -0,0 +1,12 @@
+# -*- coding: utf-8 -*-
+
+import sys
+import mpi4py
+import mpi4py_shadow
+
+mpi4py_backup = sys.modules['mpi4py']
+sys.modules['mpi4py'] = mpi4py_shadow
+
+import pymultinest
+
+sys.modules['mpi4py'] = mpi4py_backup